Talk:Cretaceous–Paleogene extinction event/Archive 2

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Hyphens v. en dashes

Shouldn't two words (i.e. Cretaceous and Tertiary) be joined with a hyphen, not an en dash? Srnec (talk) 00:27, 13 March 2008 (UTC)

This was mentioned earlier up, here. Xiong Chiamiov ::contact:: ^help! 00:57, 13 March 2008 (UTC)

Featured Article?

I have no doubt that this is a very well-written article by Wikipedia's standards, but shouldn't all good articles have a criticisms section? There are people in this world who - believe it or not - don't believe that this event ever happened. Ken Ham is one, and I'm sure that Jerry Falwell didn't believe in this either. I know I don't. Even if it's just a brief section, I think there should be some sort of mention about those who disagree about this event. (Just a suggestion; please don't get mad at me.) -dogman15 (talk) 02:13, 13 March 2008 (UTC)

The beliefs of dogmatic fools like Jerry Falwell have no place in science articles. Raul654 (talk) 02:49, 13 March 2008 (UTC)

It is interesting, no, that an article on such a controversial topic in many parts of the world has not one single mention that I can find about that controversy? It almost looks suppressed. But that's impossible. Because, as Raul pointed out, science is never "dogmatic". (N.B. I have no qualms about accepting the reality of the K-T extinction event. In fact, and with a touch of irony, I bought T. Rex and the Crater of Doom a week ago.) Srnec (talk) 03:27, 13 March 2008 (UTC)

I would like to criticize the K–T Extinction Event for killing off nonavian dinosaurs, plesiosaurs, mosasaurs, and pterosaurs. The past 65.5 million years have all been a tragic mistake. J. Spencer (talk) 03:32, 13 March 2008 (UTC)

I was there. And I watched the asteroid hit the earth. Quite spectacular. After living the past 65.5 million years, I thought I would give my best efforts to Wikipedia. OrangeMarlin ^{Talk• Contributions} 03:45, 13 March 2008 (UTC)

Do the above two users have a point? Srnec (talk) 03:47, 13 March 2008 (UTC)

Yes. We don't ascribe to anti-scientific POV's. That's all. OrangeMarlin ^{Talk• Contributions} 03:50, 13 March 2008 (UTC)

(edit conflict)::::Yeah, it's called humour. This debate has gone on ad nauseam and could be placed on a huge number of articles, but is better left on specific controversies pages. Casliber (talk · contribs) 03:53, 13 March 2008 (UTC)

So why no links to those articles from this one? (Humour is not a "point".) Srnec (talk) 03:55, 13 March 2008 (UTC)

The only controversy is what might have caused the K-T boundary. If you're thinking that Noah picked up the dinosaurs, well, keep that to a right-wing Christian article. We'll leave it alone. OrangeMarlin ^{Talk• Contributions} 03:57, 13 March 2008 (UTC)

No, this whole event falls within the controversy over Creationism. I am not suggesting that every article that mentions a date from before 4004 BC be revised, but only that an article about so famous an event as this, with lots of press coverage and lots of coverage in the Creationist literature, ought to have at least a note/mention/see also link. And you and your friends don't own this article, so it isn't up to "we" to decide what is left alone and what is not. But don't worry, I'm not going to edit it, since, as I already said, I don't have a beef with it, I only agreed with the other user that it seemed almost suppressed (which it clearly is). Less controversial subjects have controversy sections. Srnec (talk) 04:06, 13 March 2008 (UTC)

There is no controversy. Please see WP:WEIGHT, WP:VERIFY, and WP:NPOV. Throw in some WP:FRINGE for fun. OrangeMarlin ^{Talk• Contributions} 04:36, 13 March 2008 (UTC)

Man Orange, that comment hurt my feelings. I think you should refactor, or better yet delete and stop editing Wikipedia, it is the only way... Shot info (talk) 05:38, 13 March 2008 (UTC)

I did say please. OrangeMarlin ^{Talk• Contributions} 05:41, 13 March 2008 (UTC)

OK, a better way of looking for the creationist point of view is reading the article on creationism. That article sums up the position of creationism on a whole range of scientific theory, rather than a whole range of articles with which creationism is at odds with (can list darwin, evolution, anything about the geological age of the earth, dinosaurs, prehistoric mammals, ice age, come to think of it, universe, big bang theory) Casliber (talk · contribs) 06:00, 13 March 2008 (UTC)

Thankyou, but as I pointed out above, some topics are just significant enough to demand at least mention of the historical controversy around them. This is one. I ask only that the avenues for examing the controversy (which anybody coming to this article will be aware of) be opened via links and a short mention/notice. Nothing more. I leave it up to others as to how that be accomplished. Let me try to sum it up clearly one more time in case my very specific point was missed: the controversy between Creationism and science is especially volatile in this area and is of historical importance and therefore deserves mention. (How else do you explain that one of the most famous young earth Creationists goes by the name of Dr. Dino?) Srnec (talk) 06:07, 13 March 2008 (UTC)

Creationism has little to do with the KT event, regardless of how much a small minority in the United States believes it never happened. In much the same way creationism has little to do with Hydrogen or Live 8. I encourage to review WP:WEIGHT and WP:NPOV. Shot info (talk) 06:23, 13 March 2008 (UTC)

Does it occur to none of you bright scientific types that perhaps constantly mocking an opposing view is not the best way to demonstrate one's lack of dogmatism to the dogmatic? As a scientist by training but a philosopher at heart, you remind me why I only ever have serious conversations about anything with the latter. There has been no attempt to answer my misgivings. And I'm to assume that's because the answer's very plain, right? Certainly not because you don't have one... Srnec (talk) 06:07, 13 March 2008 (UTC)

because we get tired of going over the same thing over and over ? Cause we get tired of arguing with people who think that 2+2 = 4, or 5, or 6...

When a child says that the moon is made of green cheese, and it is adamant about that, you can ignore the young thing. As a philosopher, how do you recommend dealing with adults who assert the same kind of thing ?

There is not a scintilla of evidence to support creationism. In fact, it requires you to bend-over-backwards to ignore mountains of evidence (both in the literal and figurative senses) and all of modern biology, geology, cosmology, etc. It has no place in our science articles. And to be quite frank, a lot of the people who deal with these topics are tired of repeating this until they are blue in the face to people who wish to substantite dogmatic believe for an understanding of basic science. Raul654 (talk) 06:31, 13 March 2008 (UTC)

Once again, the only controversy with respect to the K-T event is possibly what caused it. It happened 65.5 mya. It happened as a result of natural and physical processes. And the non-avian dinosaurs died out at that time, and they did not go on Noah's Ark. And Dr. Dino is a creationist nutjob. OrangeMarlin ^{Talk• Contributions} 07:56, 13 March 2008 (UTC)

I must ask, I wonder what Dr. Dino is called on the "inside"? Shot info (talk) 08:07, 13 March 2008 (UTC)

Janitor? OrangeMarlin ^{Talk• Contributions} 08:39, 13 March 2008 (UTC)

"On the inside"? He's in jail? .... dave souza, talk 09:09, 13 March 2008 (UTC)

Yep, "Tax Offenses" et.al. Of course it's all part of a international evolutionist plot to drain all our bodily fluids... Shot info (talk) 09:46, 13 March 2008 (UTC)

Oh, someone needs to write an article about him. Then in every creationist article that mentions him, we can link it to the criminal. I'm just an evilotionist. Very evil  :) And I'm a dolt to miss "inside". Sheesh it was late. OrangeMarlin ^{Talk• Contributions} 15:08, 13 March 2008 (UTC)

I don't think that this page should include a section about "criticism of the factuality of the K-T exctinction event". This is an encyclopaedic article about what is known SUPPOSING it were true. There are plenty of articles in every encyclopaedia that many people would contend are based on non-events and treated as though they were. It simply is the only way to write an article without being cumbersome or overly-PC. Guess what. I am a creationist that believes that God is too good of a story-teller to leave any evidence that the earth was created only 6-thousand years ago. Why would He do that? Why not create this intricate back-story and then start the universe as if it had been around for billions of years? If he's God, that would be more interesting than making it look like it started exactly 6000 years ago. Also adds an element of faith required. In light of that possibility, even creationists can study the world AS IF it had existed for millions of years. All one needs to know is that light is reaching our planet that has required (aren't we up to) 8-10 billion years to make the journey. Thus, even if the universe were brought into existence only 6000 years ago, it was created with the appearance of being MUCH older. There is no denying that. The truth is, we cannot even prove that yesterday existed, but to take that approach to science or the study of the world/universe would be non-sensical. It doesn't matter what you believe. Studying science in this way does nothing to diminish your faith or even acknowledge that it ever happened. It just acknowledges that God was clever enough to write a background to History. BobertWABC (talk) 20:42, 13 March 2008 (UTC)

Jews (I'm talking religion not ethnicity in this case) believe that evolution and plate tectonics don't subvert the belief in a G_d. That's for the weak and those lacking faith. I don't "believe" in science, I just accept it (as long as it follows the scientific method). Well Bobert, you're a creationist I could like (yeah, I know, that didn't sound so PC). You should help out in lots of articles, because your POV would be helpful. OrangeMarlin ^{Talk• Contributions} 21:18, 13 March 2008 (UTC)

My, my. Look at what I started. I had no idea it would get this big! ;) dogman15 (talk) 01:58, 14 March 2008 (UTC)

Note the mostly fun back and forth between editors. Not sure you should break your arm patting yourself on the back.  :) OrangeMarlin ^{Talk• Contributions} 02:04, 14 March 2008 (UTC)

Balance of the article

"The Cretaceous–Tertiary extinction event was the large-scale mass extinction of animal and plant species in a geologically short period of time..." "Was." Science in this respect is looking at evidence and constructing a theory to explain it, therefore "The Cretaceous–Tertiary extinction event is the theory that..." would be more appropriate? I resent various groups saying that 'this is a scientific article!' when theories (With any amount of evidence) are stated as fact. The difference between a fact and a theory is among one of the first things taught in school, surely scientists/wikipedians should know the difference? 82.32.252.203 (talk) 11:18, 13 March 2008 (UTC)

Sorry about your resentment, the evidence is that there was this extinction, and various theories explain these facts. See evolution as fact and theory for related information, and please appreciate that our policy of NPOV: Making necessary assumptions means that we don't spell out underlying debates on every detailed article. Hope that helps, ... dave souza, talk 12:55, 13 March 2008 (UTC)

Unfortunately, theories are an important part of science. And theories are only temporary explanations for the evidence we have. That is what makes science science. And the entire article is about a theory, in a certain way. And it is explained in a matter of fact manner. If you read carefully, you can see that this theory will probably change in the future. As it has in the past.--Filll (talk) 13:01, 13 March 2008 (UTC)

Remember, I quit watching and participating in every single evolution article? Well this is why. Trolls. Meh. OrangeMarlin ^{Talk• Contributions} 15:09, 13 March 2008 (UTC)

How is trying to present a more balanced point of view being a Troll (Internet)?

"An Internet troll, or simply troll in Internet slang, is someone who posts controversial and usually irrelevant or off-topic messages in an online community, such as an online discussion forum, with the intention of baiting other users into an emotional response or to generally disrupt normal on-topic discussion."

Since when has a balanced point of view been controversial? It certainly isn't irrelevant or off-topic, and I am actually trying to make people use a less emotional/personal view. By saying that on could perhaps argue that you are being off-topic, disrupting, irrelevant, and trying to bait another user into a response.

Evidence can be interpreted in many ways, the fact that 'evidence' or 'fact' exists does not automatically prove an applied theory correct until proven wrong. I certainly understand that NPOV: Making necessary assumptions gives the writer(s) a license to use whichever assumption they find fitting for their point of view, and then defend it by waving the aforementioned policy as an argument. All theories are prone to regular reshaping and restating, what is the advantage of using such terminology as "was." You accept that this page is about a theory, then why not directly state it as such?

The article starts off stating the found evidence - I stress found because until we excavate the entire surface of the Earth, we can not say for sure, therefore statements such as "out of the found evidence..." etc is used to be fair and correct - and then degenerates to this: "Non-avian dinosaur fossils are only found below the K–T boundary and became extinct immediately before or during the event." "Are only found"? "Became extinct immediately before or during the event"? This is a definate statement! What is balanced and scientific about this? "Non-avian dinosaur fossils have so far only been found below the K–T boundary and it is thought they became extinct immediately before or during the event." Is a more balanced view. "Mosasaurs, plesiosaurs, pterosaurs and many species of plants and invertebrates also became extinct." Again, same argument. Mosasaurs, plesiosaurs, pterosaurs and many species of plants and invertebrates are also believed to of became extinct. Is more balanced. The third paragraph of the article then states "Scientists theorize that..." which is a much more neutral and balanced point of view, but then... "During the Maastrichtian stage of the Cretaceous, there was already a progressive decline in biodiversity prior to the ecological crisis indicated by the K–T boundary. After the K–T event, biodiversity required substantial time to recover, despite the existence of abundant vacant ecological niches." Again, it's theorize, believe, etc.

It seems the dividing line between what is fact/evidence has blurred with the theory of explaining it creating a gray area of mixed fact/evidence and theory. Remember that on both sides of the argument are human beings, and as such are flawed. People have points of view, agendas, and things which they feel strongly about. Nothing in life is neutral but we should perhaps strive to be, especially in such a place as Wikipedia. 82.32.252.203 (talk) 15:29, 13 March 2008 (UTC)

See NPOV: Making necessary assumptions. Of course if you've different info published in good peer-reviewed scientific journals, please cite them as sources and we can consider any changes you propose. .. dave souza, talk 15:34, 13 March 2008 (UTC)

I notice you are trying to speak on behalf of all the editors of this article, interesting. With that in mind, "'we' can consider any changes you propose?" That seems rather "I ('we') shall consider you if and when I ('we') see fit." I believe there is a policy somewhere which states that one users opinion is in no way automatically less important than anothers. I am not going to get into a debate about sources when I am not making any point about the validity of them. This seems like a knee-jerk reaction.

So you're using NPOV: Making necessary assumptions as a ticket to assume what you will, and not balance the articles wording at all? To make this absolutely clear, I do not give any weight to either side of the creationism/evolutionism argument and I am not arguing for or against either. This is simply a case of presenting it in a more fair and balanced way which you seem to for some reason, oppose.

Another opinion is certainly welcomed. 82.32.252.203 (talk) 16:05, 13 March 2008 (UTC)

Oh, there's more. You know WP:WEIGHT where we cannot give undue weight to fringe theories. But if you can find a reliable source that can verify your claims to whatever fringe theory you're espousing publicly, go ahead and add it to the article. Oh, and check out Talk:Evolution/FAQ. That'll answer most of your questions. BTW, science doesn't work on "beliefs." Sorry dude. OrangeMarlin ^{Talk• Contributions} 18:08, 13 March 2008 (UTC)

Did you even read anything of what I said? I've said it several times, and i'll say it again:

I DO NOT CARE ABOUT EVOLUTION OR CREATIONISM! This is about the grammarical balance to the article. Please, tell me what this fringe theory is, for I surely do not know myself!

May I also quote from fringe theories

Sufficiently notable for devoted articles

"* Creation science — The overwhelming majority of scientists consider this to be pseudoscience and say that it should not be taught in elementary public education. However the very existence of this strong opinion, and vigorous discussion regarding it amongst groups such as scientists, scientific journals, educational institutions, political institutions, and even the United States Supreme Court, give the idea itself more than adequate notability to have articles about it on Wikipedia."

Even if I was arguing from a completely non-balanced creationist view, on matter that would actually influence the base, or indeed any part of the overall meaning of the article, it certainly should not be considered a 'fringe theory' as stated by the actual policy itself.

However, this has absolutely nothing to do with the issue at hand, whatsoever.

What I am suggesting is that it is written in a more scientific way, not less.

A complete example, then:

"The Cretaceous–Tertiary extinction event is believed to of been a large-scale mass extinction of animal and plant species in a geologically short period of time, approximately 65.5 million years ago (mya). It is widely known as the K–T extinction event and is associated with a geological signature, usually a thin band dated to that time and found in various parts of the world, known as the K–T boundary. K is the traditional abbreviation for the Cretaceous Period derived from the German name Kreidezeit, and T is the abbreviation for the Tertiary (now known as the Paleogene) Period. The event marks the end of the Mesozoic Era and the beginning of the Cenozoic Era.

Nearly all non-avian dinosaur fossils have been discovered below the K–T boundary and it is thought they became extinct immediately before or during the event. A very small number of dinosaur fossils have been found above the K–T boundary, but they have been explained as reworked, that is, fossils that have been eroded from their original locations then preserved in later sedimentary layers. Mosasaurs, plesiosaurs, pterosaurs and many species of plants and invertebrates are believed to have also become extinct. Mammalian and bird clades passed through the boundary with few extinctions, and radiation from those Maastrichtian clades may of occurred well past the boundary. Rates of extinction and radiation then may of varied across different clades of organisms.

Scientists theorize that the K–T extinctions were caused by one or more catastrophic events such as massive asteroid impacts or increased volcanic activity. Several impact craters and massive volcanic activity in the Deccan traps have been dated to the approximate time of the extinction event. These geological events may have reduced sunlight and hindered photosynthesis, leading to a massive disruption in Earth's ecology. Other researchers believe the extinction was more gradual, resulting from slower changes in sea level or climate."

Bold has been slightly rewritten for balance, itallics were already written in a balanced state, like what I am suggesting.

First part might need to be rewritten a little bit, perhaps the evidence ("It is widely known...") should be rewritten and stated first before the theory? At the very least it sticks to the natural timeline of the article.

How is this a fringe theory? How is this non-balanced? How is this even creationist/evolutionist in any way, shape, or form? How is this my belief trying to work on science? 82.32.252.203 (talk) 22:16, 13 March 2008 (UTC)

OrangeMarlin ^{Talk• Contributions} 22:40, 13 March 2008 (UTC)

Which merely proves that you have no real counter argument - or indeed nothing to actually argue - against anything I have said at all.

If no one else has any objections, I shall make the changes at a later date and go from there. 82.32.252.203 (talk) 22:54, 13 March 2008 (UTC)

Any threats to vandalize this article will not be helpful to you, especially since this is an FA article. Moreover, you should review WP:NPA and WP:CIVIL if you wish to continue editing. OrangeMarlin ^{Talk• Contributions} 01:33, 14 March 2008 (UTC)

Vandalize? It's about improving the article, not vandalizing it.

No personal attacks? And I quote:

"Remember, I quit watching and participating in every single evolution article? Well this is why. Trolls. Meh." Personally calling me a troll, which was the first personal comment in the discussion. I replied:

"How is trying to present a more balanced point of view being a Troll (Internet)?

"An Internet troll, or simply troll in Internet slang, is someone who posts controversial and usually irrelevant or off-topic messages in an online community, such as an online discussion forum, with the intention of baiting other users into an emotional response or to generally disrupt normal on-topic discussion."

Since when has a balanced point of view been controversial? It certainly isn't irrelevant or off-topic, and I am actually trying to make people use a less emotional/personal view. By saying that on could perhaps argue that you are being off-topic, disrupting, irrelevant, and trying to bait another user into a response."

Which I believe to be a fair and just response. The last sentence is perhaps uncalled for, but you, my dear, set the standard.

BTW, science doesn't work on "beliefs." Sorry dude." Personally insulting my intelligence and calling my supposedly beliefs (Which I have have stated multiple times that I have no beliefs on this matter) non-scientific. And I quote from WP:CIVIL "Do not ignore the positions and conclusions of others."

The overall higher-than-thou "I'm right, you're wrong" attitude is very hard to miss.

Not once have you actually paid any proper attention to what I have written or even tried to give any argument against it, based on fact or otherwise.

What I have brought up is simply phrasing the article to read more scientifically.

According to you changing:

"Non-avian dinosaur fossils are only found below the K–T boundary and became extinct immediately before or during the event."

To a more neutral, more specific and overall more scientific:

"Non-avian dinosaur fossils have so far only been found below the K–T boundary and it is thought they became extinct immediately before or during the event."

Is a belief and a fringe theory. Please care to explain? If you can not, then let us get a higher power to judge for us. TleilaxuMaster (talk) 10:33, 14 March 2008 (UTC) - aka the delightful 82.32.252.203. You may bow.

Your proposals appear to give what we call WP:NPOV#Undue weight to a view which is a very small minority view among experts on the subject, and hence comes under the broad heading of Wikipedia:Fringe theories#Identifying fringe theories. "We use the term fringe theory in a very broad sense to describe ideas that depart significantly from the prevailing or mainstream view in its particular field of study." See also the notability requirement in that section. All science is provisional, but we don't write that "gravity on Earth is generally thought to accelerate bodies downwards at 9.81 m/s", to take an example. .. dave souza, talk 10:58, 14 March 2008 (UTC)

It would be appropriate to qualify statements per the suggested change if the scientists working in this area had a 75%-25% consensus on those points. It would be appropriate if it was 90%-10%. It is not appropriate when the people working in this area agree on the general points but are dickering about length of time and the relative contributions and effects of extinction mechanisms (how much is due to an impact, how much to volcanism, how much to climate change, etc.). The suggested neutral balance is a disservice to the people actually working in the field, in favor of distant observers. J. Spencer (talk) 14:32, 14 March 2008 (UTC)

It has absolutely nothing to do with a 'minority view' or any view. I have stressed this repeatedly. I am not a creationist, or an evolutionist or anything of the sort. I have not suggested changing the subject matter of the article at all in any way. Please, stop with the 'minority view', 'fringe theory' etc train of thought. This is simply irrelevant . I am not adding, taking away, or modifying subject matter.

All science is provisional, yes, but it depends on the subject matter how one phrases it. Gravity is one of the most easily tested and identified forces. It affects everything around us. When we're talking about theories like this one happened "approximately 65.5 million years ago" and changes practically every year to some extent. Are we saying that something is within the reasonable bounds of 'known fact (In the nonscientific sense)' to use such a sentence as "Non-avian dinosaur fossils are only found below the K–T boundary and became extinct immediately before or during the event."? Is this acceptable bearing in mind the fluidity of the subject matter and all together young theory?

It isn't about the lengths of time and relative contributions and effects. It's about the definate stating of the main points which give balance to everyone while stating the main belief. A funnel, in a way.

Again I shall state that I am not questioning the subject material, but rather the exactness of the phrasing used. TleilaxuMaster (talk) 14:56, 14 March 2008 (UTC)

See, the thing is, among people actually working in geology and paleontology, there isn't debate or controversy about this topic that would merit the suggested revisions. J. Spencer (talk) 15:11, 14 March 2008 (UTC)

Debate and controversy in that sense is irrelevant. Whether Scientist A thinks that there are, say, non-avian dinosaur fossils above the K-T boundry or not doesn't change that unless we excavate the entire earth above the K-T boundry, we do not know. It simply broadens the outlook of the article and keeps various camps happy while stating the main belief. —Preceding unsigned comment added by TleilaxuMaster (talk • contribs) 15:45, 14 March 2008 (UTC)

You aren't reading any link we've given you. And once again, science doesn't "believe" in anything. There is no main belief, just science. By the way, there's an old tradition in Wikipedia--once someone says "I'm not a Creationist", they usually are. OrangeMarlin ^{Talk• Contributions} 16:30, 14 March 2008 (UTC)

Yes, that's why I have quoted from them on several occasions. I also notice you have yet again given no comment on the actual subject matter, and instead got personal. TleilaxuMaster (talk) 20:54, 14 March 2008 (UTC)

Whatever. I don't feed trolls. OrangeMarlin ^{Talk• Contributions} 21:51, 14 March 2008 (UTC)

You know what, I need to give you some good faith, so I'm going to respond to you in two different ways. First, why do I consider you a troll? Every reply that you got says the same thing. You are fundamentally misconstruing what is science, what is theory and what is fact. For example, you state we need to rip up the whole earth to confirm anything. That's fine, but is more or less ridiculous. Statistics allows us to make a conclusion from small numbers. As for the extinction of dinosaurs, that's really not up for debate at this time. Sure, if a dinosaur was found in a Tertiary rock formation and was conclusively proven to not be reworked, then this article needs to be changed. But right now, through hundreds of thousands of digs into Tertiary or later rock formations, none have been found. NONE. Once more science is not a "belief." It does not have a POV. it is a set of hypothesis, experiments, predictions and characterizations that are rigorously analyzed and published. You're asking for wording changes that are WP:WEASEL, and therefore, not acceptable. And one more thing. Typical of numerous engagements between NPOV supporters and anti-science POV warriors, you tend to repeat over and over and over the same point. We all got it. We don't agree, not because we have a POV, but because you don't have support for what you write, either from other editors or from neutral sources. Bring one, just one verifiable and reliable source to the table that states unequivocally that dinosaurs did not die out at the boundary, and it would be a start (although we cannot give weight to a single article). There is a discussion as to whether the impact event happened 200,000 years before the extinction of the dinosaurs, but that's a scientific debate with just one researcher on one side and 99% of the rest supporting the K-T boundary = K-T extinction. So, just look that no one but me is responding to you. I'm responding, because I always have this hope that I can talk a Creationist out of their beliefs. But that's just the point. Beliefs are based on non-science. It's impossible to use science to change someone's "belief." OrangeMarlin ^{Talk• Contributions} 22:17, 14 March 2008 (UTC)

Thank you for responding. I am stating the same thing over in different ways to try to get you to understand what I am actually saying and trying to focus you on the actual issue. The example about 'ripping up the earth' was just to demonstrate the fallibility of definate statements. Just because you made a survey of, say, 1000 square miles and did not find a diamond, does not mean you can say "Diamonds do not exist on earth. Our survey proved this. We are right until proved otherwise." To say nothing of the fallibility of the tools used, humans, etc.

I have not once question the existance of dinosaurs. Please remove this giant 'CREATIONIST! If he's asking about the grammarical and in a way, statistical balance of this article, he must not believe dinosaurs existed either!' sticker from above my head. I have stated many times this is not the case, nor have I said anything to refute that.

The core of science is not a belief, and not once have I even hinted at this. The only time belief was brought up was when you said: "BTW, science doesn't work on "beliefs." Which was completely unfounded.

Science does not have a point of view. People have points of views, and they are the ones which execute and research the science. Of course they have a point of view to some extent, there have been many studies about how scientists given the same infomation and all come out with completely different views and summaries of the infomation at hand. It's human nature. This however, is not the point.

As for weasel words, I haven't suggested adding or changing the core infomation. "This page in a nutshell: Avoid using phrases such as "some people say" without providing sources." When have I given a statement like that?

Again I say I am not a creationist or an evolutionist in any sense. Nor was this brought up at any point in the discussion, it was purely dave souza and you who made this an issue.

Not once have you quoted me saying these things. You seem to fire an accusation off without any base, and when it is refuted simply cast it aside and make another. Please quote me and ironically give a source if you make accusations, and stop leading the discussion onto myself rather than the issue at hand.

What I am bringing up is that can one actually say something like "Non-avian dinosaur fossils are only found below the K–T boundary and became extinct immediately before or during the event" which is a completely definate statement, while maintaining a level of scientific accuracy that is acceptable? Say for instance 1% (Possibly a generous number, but it'll serve the purpose) of the entire planets K-T boundry has been analyzed for fossils, and none have been found above it. Surely one can not say "Are only found beneath..."? The statistical balance of this is surely askew? It seems a lot to assume, and this is the issue I am raising. TleilaxuMaster (talk) 23:46, 14 March 2008 (UTC)

Well done

Well done to all contributers who brought KaTie upto featured article status. Looking forward to some more featured extinction events onwiki. AshLin (talk) 07:27, 13 March 2008 (UTC)

Ahhhh, Katie!!!! LOL. OrangeMarlin ^{Talk• Contributions} 07:56, 13 March 2008 (UTC)

It's articles like this that made me fall in love with Wikipedia, as frustrating as it can be sometimes. My vocabulary just went up increased by about a dozen words.  :) Fritter (talk) 21:44, 13 March 2008 (UTC)

And this is what I love about Wikipedia--I didn't have a clue about this event. I then bought some books, downloaded articles, and read for a few weeks. As I wrote the article, I learned more and more. Several other individuals from amateur paleontologists to professional geologists jumped in and helped out. I learned. You learned. This is what Wikipedia should be about. I'm tearing up. OrangeMarlin ^{Talk• Contributions} 21:53, 13 March 2008 (UTC)

Units of time

Why is it that so many geology articles are still using this obsolete mya notation? Even the cited references use Ma. We prefer SI units on WP particularly because they are much more readily internationalized.LeadSongDog (talk) 14:14, 13 March 2008 (UTC)

See mya, and remember this is an article for the general public. Ta, .. dave souza, talk 14:34, 13 March 2008 (UTC)

Please do. Note also what's on Annum and talk:mya (unit) -- I've been trying to get some motion on this for many months now. WP should never talk down to the general public. We should adopt the best practices used by experts in the field, explaining jargon where necessary. In this case, those experts are the International Commission on Stratigraphy (see ref 1 to the article). The timeline here uses Ma. If we think it's necessary to explain the unit inline, the text could read "65.5 Ma (65.5 million years) before present" to meet the principle of least astonishment, although my personal assessment is that it is reasonable to let the few astonished readers click on the Ma instead (at least outside the lead). LeadSongDog (talk) 16:22, 13 March 2008 (UTC)

When we were editing this article for FAC a few months back, we couldn't get consensus from proofreaders, editors, or anyone else. So, we decided to be consistent. I wikilinked mya, just to make sure no one missed what it meant. OrangeMarlin ^{Talk• Contributions} 18:04, 13 March 2008 (UTC)

Sure you aren't thinking of another article? I couldn't find it in the talk archive.LeadSongDog (talk) 20:29, 13 March 2008 (UTC)

This is my first and only geological article that I've written and pushed through the FAC process. So I'm guess it's here. It might have happened on SandyGeorgia's page instead, but let me look back over the archives. OrangeMarlin ^{Talk• Contributions} 21:22, 13 March 2008 (UTC)

It was actually here during the FAC discussion. You need to click on the hidden discussion with SandyGeorgia. It was a non-resolution resolution. IOW, we kind of gave up. But I'm all for consistency across articles, since it's really not going to change the fundamental meaning of this article. However, if this is a sneaky way of putting Living dinosaurs in here, we will not be amused. LOL. OrangeMarlin ^{Talk• Contributions} 21:29, 13 March 2008 (UTC)

Thanks, now I get it. Wikipedia talk:Manual of Style (dates and numbers)/Archive 78 danced around it, but never quite addressed the question of whether to discourage use of mya. Everyone seemed to prefer ka, Ma, Ga although there was some confusion over capitalization (SI usage for multipliers is quite unambiguous-k for kilo, M for mega, G for giga, T for tera, but it seems this wasn't universally grasped). Once archived, the discussion ended with little change to MOS:DATE. I suppose that Wikipedia talk:Manual of Style (dates and numbers) is still the right place to pursue the question. I'll go there.LeadSongDog (talk) 07:27, 14 March 2008 (UTC)

I hear that place can be a bit...well...challenging.  :) OrangeMarlin ^{Talk• Contributions} 16:47, 14 March 2008 (UTC)

Well, supertankers take a long way to turn, but carry a lot of extinct critters. ;/) LeadSongDog (talk) 17:42, 14 March 2008 (UTC)

LMAO. Good one. I think what the problem is for a lot of science articles (aside from the attacks by anti-POV pushers, see below) is that there's a desire on one side to write articles for the common "American" (our science education is weak, all you need to know is that Evolution is merely a theory, but I rant) or write the article for a more sophisticated and educated readership. This article is written for a 20 year old American. I'm not sure Ma or mya is going to change that one way or another.OrangeMarlin ^{Talk• Contributions} 17:51, 14 March 2008 (UTC)

Iridium

First paragraph: Should it not say "with a geological signature, usually a thin band of iridium dated to that time"? 64.160.20.30 (talk) 14:34, 13 March 2008 (UTC)

You're allowed to make changes. However, the signature of iridium is not the only indication of the boundary. There is some debate in the scientific community (really a few researchers on one side) that state the boundary predates the extinction by a few hundred thousand years. And "usually" is not word that should be used in an encyclopedia article. OrangeMarlin ^{Talk• Contributions} 15:11, 13 March 2008 (UTC)

With respect,it was the presence of iridium in the same layer al over the world that was the proving factor in the meteor theory. As iridium is not a naturally-occurring element on Earth, and since most of it comes from outer space, a lot of it accumulating all over the world at the same time would come from an impact event.- Arcayne (^{cast a spell}) 22:21, 13 March 2008 (UTC)

Actually this article tries to limit the discussion of geological theories of what caused the K-T boundary as opposed to the extinction itself. They may not be tied as closely together as one thought. My suggestion is that it should be brought to the K-T boundary article, which is separate and distinct from this one. OrangeMarlin ^{Talk• Contributions} 22:28, 13 March 2008 (UTC)

Well, perhaps it would be helpful if you were to outlne why you personally feel the events are not "tied as closely together as one thought". - Arcayne (^{cast a spell}) 08:12, 14 March 2008 (UTC)

I have no personal POV. Just read the article and the supporting citations. OrangeMarlin ^{Talk• Contributions} 16:32, 14 March 2008 (UTC)

Formations

I was checking the article's revisions over the last few hours and noticed that the MacLeod et al 1997 paper is cited regarding the Hell Creek, Scollard, and Lance Formations of Montana as the best sequence of dinosaur fossils at the K-T Boundary. This was a bit surprising geographically, as although all three are approximately the same age and considered in the Lancian North American Land Mammal Age, the Lance is largely Wyoming and the Scollard from Alberta. I checked the link to the text-only version of the article, and only the Hell Creek was mentioned, so I was wondering if perhaps the wrong MacLeod article was cited, as the point that these formations are the best for dinosaurs at the K-T is correct and has been stated before (even if they aren't all in Montana). J. Spencer (talk) 14:43, 13 March 2008 (UTC)

I'm the one who wrote most of the article with the MacLeod article (which is a great review of the extinction event). So let me just say, "Dammit Spencer, I'm a doctor not a paleontologist." I think you should fix it appropriately, because when I read the sentence written, and I think "OK that sounds reasonable". Apparently you don't! I can't for the life of me remember why I wrote it, but it's possible I was using another MacLeod article (he's written so many, it's going to take work to find the right one). OrangeMarlin ^{Talk• Contributions} 15:14, 13 March 2008 (UTC)

Well, I made a swap that I think keeps the spirit if not the letter of the original paragraph. J. Spencer (talk) 16:33, 13 March 2008 (UTC)

You rock! OrangeMarlin ^{Talk• Contributions} 18:02, 13 March 2008 (UTC)

Genetic bottleneck?

Can we see the signatures of a genetic bottleneck in DNA of modern animals caused by the KT event? Count Iblis (talk) 15:26, 13 March 2008 (UTC)

I'll bet that the ensuing 65.5 million years would mask any DNA signature, but I'm not a biochemist. Furthermore, many clades didn't go through a bottleneck (like was seen with the Ordovician-Silurian extinction events, where there were numerous genetic bottlenecks)--in the case of the K-T event, clades either went extinct, or survived intact. In the world of extinction events, I would say that this one is the best studied, but really isn't very dramatic compared to the P-T extinction. It's the death of the non-avian dinosaurs that makes this event so popular. OrangeMarlin ^{Talk• Contributions} 18:44, 13 March 2008 (UTC)

Un-Neutral

This article is completly biased, it states it as a fact instead of a theory. —Preceding unsigned comment added by 66.45.175.2 (talk) 20:00, 13 March 2008 (UTC)

See theory, WP:NPOV and WP:NPOV/FAQ. Methinks the word doesn't mean what you think it means. .. dave souza, talk 20:31, 13 March 2008 (UTC)

Methinks? How Shakespearean of you! OrangeMarlin ^{Talk• Contributions} 21:20, 13 March 2008 (UTC)

The main impact image

Can someone explain why we are using an artist's rendering of the CT event that looks like an over-large nuclear mushroom cloud? It's a pretty inaccurate depiction for several reasons. Before removing it, I wanted to get some feedback first on what to replace it with. - Arcayne (^{cast a spell}) 22:18, 13 March 2008 (UTC)

Please find a reasonable replacement before deleting it. We're using images that we are licensed to use, so that limits your choices. Moreover, I don't agree with you. A nuclear explosion wouldn't be that large. The artist's rendition is more indicative of the size. OrangeMarlin ^{Talk• Contributions} 22:30, 13 March 2008 (UTC)

Is there any reason to think the impact event shouldn't look like "an over-large nuclear mushroom cloud?" Although the mechanism was kinematic rather than nuclear, my understanding is any very large explosion will tend produce a mushroom cloud, as stated in Wikipedia's article on the subject. I note the scale of the explosion is unclear from the picture, but the artist's vantage point appears to be from space or near space, indicating the fireball is gigantic. Fritter (talk) 23:20, 13 March 2008 (UTC)

Oh, I am not arguing with the size of the explosion, but rather all the pretty, coloring extending high enough into the atmosphere that a great big yellow flaming cloud would not only be silly but rather impossible.

If, using my hand, I can hit you in the face with the equivalent force of a baseball bat, my hand is not going to leave splinters from the wood of the baseball bat, nor is the resultant sound going to be that of yours truly hitting a home run. I hope that the metaphor in itself makes my point, but if not, then; something impacting with the same force as lotsa nuclear explosions is not the same thing as lotsa nuclear explosions. There would be force, yes. Might even be superheated air and ash, but it wouldn't be a flaming ball. Now, before someone suggests that the meteor would ignite the world's atmosphere, please consider that the Manhattan Project scientists thought exactly the same thing about the detonation of nuclear bomb. They were wrong too, as several subsequent above-ground detonations have conclusively proven. Our atmosphere doesn't work that way. What caused the event was the resultant ash in the air, which blocked the sun and cooled the airth, which killed the plants, which killed the herbivores and the carnivores soon followed.

While the image is pretty, it isn't really all that accurate. We should be able to find an image that is at least more scientifically accurate and not sensationalism CGI. - Arcayne (^{cast a spell}) 06:47, 14 March 2008 (UTC)

I believe the picture was done by NASA scientists to depict the earth upon impact with a larger meteor. It is quite accurate. OrangeMarlin ^{Talk• Contributions} 06:51, 14 March 2008 (UTC)

Might I trouble you to cite that it was done by NASA scientists, and not some CGI cartoonist hopped up on a case of Red Bull? I believe I had just spent two paragraphs rather clearly pointing out why it is actually INaccurate, so perhaps absolutist statements aren't really the way to go here. While you are seeking out that NASA citation, perhaps you could find one that cites how meteor impacts look exactly like a nuke going off. Honestly, if some NASA scientist actually thinks that a flaming cloud extends that far up into the atmosphere, our space program is in greater jeopardy that I had previously imagined. - Arcayne (^{cast a spell}) 08:06, 14 March 2008 (UTC)

<undent> While making no claims to knowledge in this field, I have to hand a copy of The Great Extinction; What Killed the Dinosaurs and Devastated the Earth, by Michael Allaby and James Lovelock. (see ISBN 038518011X) which goes into some detail about the Alvarez hypothesis on the effect of a large lump hitting the Earth. On impact with the sea, rock and the sea where they met would be dissociated into atoms, stripped of electrons to form an extremely hot plasma cloud, a very dense gas which would then rise, not through convection but because there was nowhere else to go, forming a fireball carrying between 6,000 and 60,000 billion tonnes of matter into the atmosphere at about escape velocity so that some could have gone into orbit. The hot, dense, plasma would have been almost disc shaped, rising extremely quickly as a very wide barrel of fire. That, of course, is just the start. It's an ancient source, from the days before macs roamed the earth, but on that basis the image seems pretty reasonable. ... dave souza, talk 08:46, 14 March 2008 (UTC)

With respect, Dave, the reliability of a 25 year-old book on the subject isn't very useful, considering the work that has been done to advance the science of the event since them. Now, I know that you were fortunate enough to have that book on hand, and it isn't a bad book at all (note I am not bothering to discuss the synthesis issues with the book's usage). It's just dated, and the science is somewhat inaccurate. Rock and sea would not be atomized. Vaporized (as in rendered into ash that scatters into the atmosphere), yes, but not rendered into atoms. And there can be no fire where there is no atmosphere to fuel it. If anything it would have looked something like this: )(.

Course, I don't hold the Lucasian Chair either, but the image of a great grandpappy of nuclear explosions seems sensationalistic and inappropriate for an encyclopedia. - Arcayne (^{cast a spell}) 09:10, 14 March 2008 (UTC)

 ! ... dave souza, talk 10:33, 14 March 2008 (UTC)

For what it's worth, the only part of the image which came from NASA (according to its description page is the cloud texture. I'd be very interested to know how accurate the depiction was (although I doubt there's much scientific literature speculating on the subject!) Verisimilus T 11:08, 14 March 2008 (UTC)

The main impact image - arbitrary break

<RI>This conversation went from mildly interesting to tendentious. But I hope I can put this to bed:

• Don Davis (artist) is an artist, and his notability, expertise in this field, and reputation is unparalleled.
• Artist website
• Painting website
• Because of licensing limitations from NASA, Fredrik (talk · contribs) recreated the image for us, utilizing the images from Don Davis.
• Excerpt from book about an impact
• Discussing a fireball
• Quotes below

"The energy of the K-T impact is estimated at 108 MT from the size of the Chicxulub crater, and a

consistent value of the size of the impactor (10-15 km diameter) is derived from the observed extraterrestrial component in the boundary layer. Immediate effects of the impact included blast and the generation of tsunami (since the impact occurred in a shallow sea). However, the primary agents of global stress appear to have been a short-lived firestorm from atmospheric heating of reentering ejecta, followed by a persistent (months to years) blackout due to particulates suspended in the stratosphere. Other possibly important effects include chemical changes in the oceans and

atmosphere and large climatic oscillations following the impact."

• And:

"The global environmental stress from the K-T event was dominated by a prompt firestorm

followed by longer-lasting dust loading of the atmosphere. There is direct evidence in the boundary clay for the soot produced by burning a large fraction of the terrestrial biomass. In addition, analogous effects seen following the impacts of Comet Shoemaker-Levy 9 with Jupiter in July 1994 have been extensively modeled (Boslough et al., 1994; Zahnle & MacLow, 1994, 1995). A global firestorm can be ignited by hot debris falling back into the atmosphere on ballistic trajectories from the ejecta plume, as first suggested by Melosh et al. (1990). Most of the energy is deposited in the mesosphere (where meteors shine), with radiative heating of the lower atmosphere and surface. Toon et al. conclude that while this mechanism was important in the K-T event, where it was the probable direct cause of the extinction of large land animals such as the dinosaurs, it does not produce surface temperatures high enough for ignition at impact energies below 107

MT."

I think this settles this. And you know what, I really don't care about the image. OrangeMarlin ^{Talk• Contributions} 16:46, 14 March 2008 (UTC)

With respect, I am not sure how any of this discussion is tendentious. Perhaps you could extend a bit more good faith that my posts are meant for the good of the article. I haven't edit-warred over the image (in fact, I came here first to discuss the matter without ever touching the image). I haven't called anyone a doo-doo head (and wasn't really inclined to), and am not - in the text of the 'tendentious editing' article - trying to "right some great wrong". Maybe you could explain how my discussing the matter (and not simply accepting absolutist statements, which almost always come across as bias) is tendentious.

I will say that I did learn some nifty tricks, like how to add a pdf symbol to quoted text. I actually read the entire article, then followed the references provided by that article (which is what they are there for, to my reckoning). Melosh et. al's cited work talks about super-heated air (not plasma) that likely caused wildfires and helped sustain firestorms, in much the way that paper can burst into flame when placed in a 500 plus degree oven. Melosh didn't make a mistake in noting the wildfires and firestorms; it was simply an error of interpretation by folk here who aren't geologists or rocket scientists well-versed in thermodynamics. Firestorms are not plasmic fires, nor are they changing matter at the atomic level.

the whole point of this discussion is to point out that while the painting may convey a visually connective (almost all of us have seen imagery of a nuclear explosion) image so as to simulate that which we can comprehend, the painting is likely not an accurate visual interpretation of the impact event. - Arcayne (^{cast a spell}) 20:02, 14 March 2008 (UTC)

I gave you good faith. Now it's gone. Sorry. OrangeMarlin ^{Talk• Contributions} 20:26, 14 March 2008 (UTC)

Um, okay. You still didn't exlain what it was I did that was tendentious, aside from apparently daring to engage you in discussion of the topic. Maybe grow up a little. - Arcayne (^{cast a spell}) 22:57, 14 March 2008 (UTC)

<RI> Please see Comet Shoemaker-Levy 9#Impacts. It's a real world observation in our lifetime of what an impact will do. Unfortunately, we do not have pictures of K-T event to prove this. OrangeMarlin ^{Talk• Contributions} 20:52, 14 March 2008 (UTC)

Yep, it's an impact alright - of asteroids into a gaseous mass (Jupiter is not a solid) that have a different chemical composition than that of Earth. Apples and oranges: both similar in shape and both plantlife, but different in just about every other way. - Arcayne (^{cast a spell}) 22:57, 14 March 2008 (UTC)

Energy from an explosion is still energy regardless of the source of that energy. The picture is appropriate for a representation. Orange is correct in saying that this is an example of WP:TE, it isn't a discussion as one side isn't reading the responses. Shot info (talk) 01:56, 15 March 2008 (UTC)

Thanks for the good, faith, Shot Info. I was reading the responses, since I responded to them. What is the matter with some of you, that you see dissent as tendentious? Lesson number one of Wikipedia: if you cannot deal with people questioning your edits, find some other playground. Jeez. - Arcayne (^{cast a spell}) 03:21, 15 March 2008 (UTC)

I find your comments more puzzling than tendentious; I don't understand your focus on "changing matter at the atomic level." This seems beside the point. As Shot Info noted, energy is energy. Highly energized materials may glow even if there is no combustion or nuclear explosion. Metal will glow if heated enough. Lava of course glows. The impact event at Chicxulub is described as the equivalent of more 100 teratons of TNT. Some of that energy would go into shock waves through the atmosphere and the earth. Some energy would go into deforming and moving huge amounts of earth and water. And some energy would go into heat. Even if only 1% of the energy is lost as heat, which sounds pretty conservative, that amount of energy is still 20,000 times greater than any nuclear bomb humans have detonated (assuming Tsar Bomba was 50 Mt). (In fact the difference must be even larger, given that only a portion of a nuclear bomb's energy goes into the fireball.) That amount of heat generated in one event would have created a spectacular explosion, making the artist's rendering (in the first image) a reasonable conjecture in my opinion. This was a lot more than just kicking up some dirt. In the new image a land mass is visible which may bring up questions of scale. Fritter (talk) 06:11, 15 March 2008 (UTC)

That picture really should be removed. The K-T event was caused by the impact of a large asteroid or comet. The object in the picture, while obviously not a "cloud", is apparently the size of a small moon. Why include such a picture, anyway? This is a science-related article, not an airbrushing contest. Johnskeller (talk) 02:03, 15 March 2008 (UTC) —Preceding unsigned comment added by Fritter (talk • contribs)

Actually, Johnskeller, the image was very recently changed. Were I not to assume good faith here, I would think that this image was substituted so that people would look at this impossibly large mass (research from the article places the likely size of the asteroid at approximately 10 kilometers (6 mi) in diameter, about the size of Manhattan which, while cited as being from this source doesn't actually appear in that source) slamming into the earth and consider that people might settle for the lesser of the two unlikely images. In fact, even considering that this might be a cynical edit would be a total lack of good faith on my part, so I am going to assume that Orange sought out to find an image that wouldn't be controversial. I am not sure that the replacement was such a good one. The size of that asteroid looks a hell of a lot bigger than 6 miles across - it look about the size of Australia, which I think might have broken the Earth. - Arcayne (^{cast a spell}) 03:47, 15 March 2008 (UTC)

Dude. I don't care what you do. Change it don't change it complain about it. Your choice. OrangeMarlin ^{Talk• Contributions} 06:01, 15 March 2008 (UTC)

Okay, thanks for your permission. I just thought you might have handled being disagreed with somewhat better. Better make that scotch a double; you need to calm down somewhat. - Arcayne (^{cast a spell}) 08:26, 15 March 2008 (UTC)

Oh, by the way, it's well known on Wikipedia than the second you state you're giving good faith, is the point when you're not.OrangeMarlin ^{Talk• Contributions} 06:02, 15 March 2008 (UTC)

Prolly. However, failing to give AGF (after repeated requests) can occur entirely unbidden, apparently. Sleepeth well cuddling a bottle of Glenmorangie 18 year, sweet prince. - Arcayne (^{cast a spell}) 08:26, 15 March 2008 (UTC)

If the bolide is depicted impacting the Yucatan it is not nearly as big as Australia. But it does seem to be about as wide as Central America, which still seems too big. Not a big deal though. EDIT: come to think of it while the crater is pretty big the bolide itself should be a lot smaller (unless the gray part is just the dust cloud) Fritter (talk) 06:11, 15 March 2008 (UTC)

Huh. I never saw that. I always thought it was an asteroid, and not a cloud from it. as fr the sizing, you may be right. How big would Manhattan look in that image of the earth. Kinda hard to depict something so small that still believably causes as much havoc as it did. Fragile ecosystem... - Arcayne (^{cast a spell}) 08:26, 15 March 2008 (UTC)

Impact image options

To summarise the NASA statement above, *Quotes below

"The energy of the K-T impact is estimated at 108 MT from the size of the Chicxulub crater, and a

consistent value of the size of the impactor (10-15 km diameter) is derived from the observed extraterrestrial component in the boundary layer. Immediate effects of the impact included blast and the generation of tsunami (since the impact occurred in a shallow sea). However, the primary agents of global stress appear to have been a short-lived firestorm from atmospheric heating of reentering ejecta, followed by a persistent (months to years) blackout due to particulates suspended in the stratosphere." and "The global environmental stress from the K-T event was dominated by a prompt firestorm

followed by longer-lasting dust loading of the atmosphere."

• 
  Made by Fredrik. Cloud texture from NASA image.
• Source: http://nai.arc.nasa.gov/
  Source: http://nai.arc.nasa.gov/
• 
  Nasa afbeelding.. van: http://www2.jpl.nasa.gov/files/images/captions/p45062.tx
• 
  K/T extinction event theory. http://www.nsf.gov/news/special_reports/dino/ultimate.jsp PD as created by NASA

There are also some other impact event images in the commons, not specifically about KT. The first image is the original one that began the argument, the second one was substituted and has been objected to for reasons of scale. In my opinion the third image is too static looking, a problem with the first two where the bolide is shown, while the fourth image is more informative and overcomes the objections. .. dave souza, talk 09:17, 15 March 2008 (UTC)

David, thanks for bringing some of these options here for us to look at. I guess my problem with scale is there in the four options. the fourth one appears to give the energy signature that's the most realistic, but I am a bit worried about the scale issue again. The bolide looks so huge in comparison to the landscape it is impacting (that sucker appears to dwarf the coastline depicted - I guess Manhattan is a big mofo), but if others can live with #4, then so can I. - Arcayne (^{cast a spell}) 14:49, 15 March 2008 (UTC)

I like Nr 2 - and the size issue can be (in page layout terms) worked around by blowing up the picture. Sure, it won't become clearer that way, but at least it won't show up as strangely small for most users. Ingolfson (talk) 09:57, 16 March 2008 (UTC)

I edited the NASA statement above. It had lost formatting. The text said 108 MT (megatons). The correct number is 10⁸. The image in the article showed an impact in object orders of magnitude more massive than reality. If readers are surprised by the small size of the real object, they may be stimulated to learn more about asteroid impacts. I have substituted the first of the image options. Perhaps this will help readers understand the fragility of Earth in the cosmic environment. Harold f (talk) 05:48, 18 July 2008 (UTC)

Good point about the energy, Harold f. Last time I edited this I included Alvarez' estimate, which dwarfed all human nuclear arsenals combined.

None of the image options is satisfactory. In A and B the bolide's far too big (it's generally thought to have been 10 km in diameter, while the Earth is about 12,000 km). Scaling the bolide relative to the whole Earth is a no-win situation, so in principle localised views such as C & D are better. But in D the pic is so narrow that the bolide looks ginormous, although comparison with the pretty straight horizon shows that it is really not so huge. B and D also make it look like the bolide impacted at near 90 degrees to the surface, but I've read that it was only 30 degrees from horizontal and going roughly north, which is why N. America suffered worst from the splash damage. C is nice in principle as it shows the moment of impact (which should be more oblique), but has too little contrast and too much detail for a thumbnail.

I'm no artist, but I have some ideas. If a real artist is interested in taking this further, I can rough something out as a basis for the real artist to produce a decent pic. -- Philcha (talk) 11:48, 18 July 2008 (UTC)

• • No asteroid image is satisfactory for the introduction to this article: because although some of you may not like it, the asteroid impact as cause of the KT event is disputed. Thus any image of the impact should not dominate the article - as it currently does - but be placed by the relevant section. 90.231.2.252 (talk) 13:56, 25 July 2008 (UTC)

Logic mistake?

"For example, it is thought that ammonites were the principal food of mosasaurs, a group of giant marine reptiles that became extinct at the boundary." - This doesn#t make much sense to me, though I am not an expert. Ammonites are small to tiny animals, while the mosasaurs where large hunting reptiles. I can't see predator animals with teeth larger than their prey subsisting on such small fry. Shouldn't this say something along the lines of that specific foodchain collapsing, with the mosasaurs at the top also dyding out as a result? Ingolfson (talk) 09:53, 16 March 2008 (UTC)

The claim is referenced and a google search reveals the opinion is common, though not universally held. Perhaps ammonites were more of a snack than a full meal. Regardless, it's unscientific to assume a priori what the animal did or did not eat. Fritter (talk) 13:09, 16 March 2008 (UTC)

Ammonites were not small tiny animals. Certain species could grow conchs up to a metre or more in diameter (not including soft parts), although I'm not too familiar with late Cretaceous families. In any case, a blue whale is a pretty big animal- a krill is not. There's no logical fallacy. Badgerpatrol (talk) 14:16, 16 March 2008 (UTC)

Apparently some ammonites were 2 metres (6.5 feet) in diameter, quite a large snack! . . dave souza, talk 19:44, 16 March 2008 (UTC)

Yikes. I hate creepy-crawly things, and when I read about giant cockroaches and scorpions, I get nightmares. T. rex doesn't scare me half as much as a 2 meter scorpion. OrangeMarlin ^{Talk• Contributions} 23:36, 16 March 2008 (UTC)

I imagine they probably had the same nightmares about us. They probably felt, 'hey, its our turn to rule, we've waited in line! What's up with the pink, hairless squirrel butting in?' 'Course, that's speculative. Scorpions and roaches may have planned the CT event, and been too busy doing high math to worry about the pink squirrels with their crazy flints/puppets. :) - Arcayne (^{cast a spell}) 18:32, 17 March 2008 (UTC)

Tertiary?

An anon removed "(now called the Paleogene Period)", and on looking at the Tertiary page it actually seems to extend further, so I've changed it to "(in modern terminology the Paleogene Period on to and including the Pliocene epoch)". Someone who knows about these things might care to improve that. .. dave souza, talk 19:44, 16 March 2008 (UTC)

Dave, I feel that your edit should stand. T does stand for Tertiary, and the sentance as it stands does a fine job of explaining why it is called the K-T extinction.

As terminology settles down, we may consider revising the sentence. The term "Tertiary" is now depreciated in favour of the Palæogene and Neogene - although the precise delimtation of these is not quite settled. As we're only interested in the start of the period, informing the reader of when it ends (using unfamiliar jargon) is probably of somewhat limited utility. Given time, the event may eventually be rebranded the "K-Pa extinction" - but the old name is probably deeply enough entrenched to grant it some posterity, just as the depreciated "Carboniferous" period is unlikely to disappear from the text books any time soon. Verisimilus T 23:25, 16 March 2008 (UTC)

I agree. I think the footnote explains it sufficiently for the time being. Although it has been argued that it should be called the K-Pa extinction event, and we could redirect if we changed the name, I think that it's early enough in the "evolution" of the term to wait a few months. I like the idea of letting it settle down. OrangeMarlin ^{Talk• Contributions} 23:35, 16 March 2008 (UTC)

I've slightly altered your edit Dave. The base of the Tertiary (which is all that really matters in this context) is well defined. The top is a bit controversial at present, because the status of the Quaternary as a chronostratigraphic unit is not 100% established. I think the latest proposal is to extend the Quaternary into about the later quarter of the Pliocene, and have the Neogene persist to the present day (meaning in a certain sense that the Tertiary never ended). To be honest, I'm not really familiar with the very latest developments myself. It is certainly true as Verisimulus says that "Tertiary" is not a technically accurate term (it's not really a formal unit of geological time) and that, strictly speaking, Palaeogene and Neogene should be deferred to in preference- this isn't going to change any time soon; as far as I'm aware the matter is settled. Scientifically, there is no doubt that use of the "K-T" terminology is 100% wrong- but it is still widespread colloquially and indeed within even recent scientific literature. The Carboniferous still exists as a system in full use, by the way. It is technically split into the Mississipian and Pennsylvanian sub-periods, although in everyday practice this terminology (although entirely correct) is traditionally I think not as widely used outside of North America. It's not in any way wrong or old fashioned to talk about the Carboniferous as being the system between the Devonian and Permian (although as it often is with these things, the situation is complicated). Badgerpatrol (talk) 06:02, 17 March 2008 (UTC)

Verisimulus, I've just seen your note on the talk page of Carboniferous (whilst lazily checking my facts after the event...)- do you mean to say they've changed it again, post-2004???!!! Where did you see this? In the most-recent stratotype listing (which claims to have been updated in January) the Miss and Penn are not full systems.... Badgerpatrol (talk) 08:11, 17 March 2008 (UTC)

It's a relatively recent development; a colleague informed me that it was the new official status as of late January. I didn't question him further and had a good scout round on the web before changing the article itself, but couldn't find a mention of it, so I assume it is still "in press", but has reached a stage where it's been circulated around the relevant stratigraphic mailing lists. Watch that space, I guess... I'll post up a verifiable source as soon as it crosses my path! Verisimilus T 11:10, 17 March 2008 (UTC)

The ICS site has revised the International Stratigraphic Chart (PDF file) as of January 2008. It doesn't list Mississippian or Pennsylvanian. I assume BadgerPatrol is referring to a more localized chart.LeadSongDog (talk) 15:23, 17 March 2008 (UTC)

Yes, that (and the golden spike list) was what I was referring to. It seems to show the M and P as sub-periods of the Carboniferous. Doesn't mean that Verisimilus is mistaken though, these things take time to filter down and be agreed upon. If they have done it, I'm a bit surprised, since the subdivision is so closely associated with the Carboniferous system in America, having less relevance elsewhere. Anyway, should it become an issue, we can always try and find someone with the relevant expertise ;-). Badgerpatrol (talk) 16:20, 17 March 2008 (UTC)

Wildfires

This article doesn't make much mention of the impact of wildfires; the hypothesis - and its debunking - are interesting, and I feel deserve developing into at least a paragraph or two. This recent article in Geology has an interesting explanation for the sooty evidence in terms of the combustion of fossil carbon. I would incorporate it into the article myself, but haven't got the energy to get into FA-contribution mode and do a proper job of it! Smith609 Talk 15:04, 5 May 2008 (UTC)

One of the authors of that particular article is a rather hot young blonde TV documentary star, if my memory serves me correctly, which makes it even more interesting. Not sure about that article itself but the wildfire debate in general certainly merits attention because of the climate change angle. I wouldn't say it was completely debunked, but recent work has been excellent and had a significant impact and should certainly be mentioned. Badgerpatrol (talk) 15:35, 5 May 2008 (UTC)

"went" v. "became" extinct

Just a small point, I think... I'd like to hear people's opinions. I hear it all the time, but really hate the phrase, "Dinosaurs (or whatever) went extinct." I prefer, "Dinosaurs became extinct," because extinction is a state of being, not a place. Anyone care if I change this? Grumpy otter (talk) 18:36, 14 May 2008 (UTC)

If we're really getting pedantic, extinction is the adjective describing something which is no longer alive. "Brontosaurus populations died out" would be a better choice in most uses.LeadSongDog (talk) 20:09, 14 May 2008 (UTC)

Sorry, but "extinction" is a noun. "Extinct" is an adjective. There is nothing grammatically incorrect about becoming an adjective, such as "She became pretty." Grumpy otter (talk) 20:20, 22 May 2008 (UTC)

Picture obscures text

I don't deal with graphics so don't know how to fix this--but the wonderful picture of the K-T boundary overlaps some of the text in the lede. Can someone adjust it? Grumpy otter (talk) 18:40, 14 May 2008 (UTC)

"Geological cause of extinctions"

This section heading is inaccurate, as a bolide impact would be an astronomical event. The whole section also fails to make the distinction between killing mechanisms and triggers. Last time I edited this article it included a section "What makes a good theory", which made this distinction, although it wasn't brought out in the discussions of individual theories. The article Permian–Triassic extinction event does a fair job of showing the connections between extinction patterns, killing mechanisms and triggers (further work is required, and I'm checking out some sources); Cretaceous–Tertiary extinction event needs to do the same. Philcha (talk) 22:48, 14 May 2008 (UTC)

QUESTION: While the astronomical event theory is plausible for mass extinction on land (impact -> dust -> colder climate/reduction of photosynthesis -> reduction in plant life -> reduction in herbivores -> reduction in carnivores), this seems less plausible for the marine extinction. Yes the majority of marine plants (plankton) require photosynthesis, but a reduction in plankton should impact bony fish and cartilaginous fish equally. The article seems to suggest a difference in extinction between these two classes of fish. —Preceding unsigned comment added by 66.245.157.245 (talk) 20:20, 4 October 2008 (UTC)

Redirect

I dunno how to do dis but can someone redirect "dino extinction" to this page? That would be nice.

208.102.175.102 (talk) 23:49, 14 May 2008 (UTC)

You're looking for the ebonics wikipedia.--Fletcher (talk) 00:08, 15 May 2008 (UTC)

Wrong ref?

The paper by Keller et al (2004) is used three times as a source in this article. I have no complaints about the other two references, but the 2nd last alinea under the section "impact event" should not use that paper as a source. The text reads:

Identified in 1990 based on the work of Glen Penfield done in 1978, this crater is oval, with an average diameter of about 180 kilometers (112 mi), about the size calculated by the Alvarez team.

This is explained by Keller c.s., BUT their main point was to disprove the Chicxulub impact hypothesis by showing the impact predates the K-T boundary by 300.000 years. So they don't agree with the conclusion drawn in this sentence. One might argue that they did summarize the earlier research before proving it false in their paper, however I think it is strange to have them as source instead of this earlier research. Woodwalker (talk) 13:18, 23 May 2008 (UTC)

Duration

Wouldn't a climate change such as the one caused by this extinction last for several hundred thousand years? RingtailedFox • Talk • Contribs 02:37, 18 June 2008 (UTC)

Not sure precisely what you're asking, but actually no. It might last just for a few years, enough to destroy a lot of life, but not long enough to destroy all of life. But I might not understand your question. OrangeMarlin ^{Talk• Contributions} 03:17, 18 June 2008 (UTC)

I could have been more clear, you're right. What i mean was this: say the asteroid struck on Day 1, 65,000,000 BP. would the skies be dark for only 3 years, 300, 3000, or 3,000,000? would that trigger an ice age? Whenever i see the "K-T Boundary" in the rocks, it's fairly thin, so how many years would its thickness be? (i hope that's a bit more clear...) RingtailedFox • Talk • Contribs 05:10, 18 June 2008 (UTC)

Any atmospheric affect from a so-called asteroid strike would be short term, and any particulate matter cast into the atmosphere would return to earth in a year or so. The boundary is thin because the type of sedimentation represented by the boundary lasted for a few thousand years before a much longer period of a different deposition process occurred. Keep in mind that each layer is a recording of what was laid down as material that is later turned into rock by geological processes. The layer represents what happened AFTER the event. Hardyplants (talk) 05:22, 18 June 2008 (UTC)

Your question about the thickness and how long the it toke to form the layer is dependent on the rate of deposition. Just because a rock layer is thin or thick, does not mean there is any correlation between how much time they represent. Some thick layers are put done very thickly in a short time period, while other layers might be thin but have taken millions of years to be deposited. This also ignores the fact that layers also suffer from erosion too, and might have been much thicker before they were preserved. So a good understanding of the history needs to made from as wide a survey of the rock strata as possible. Hardyplants (talk) 05:45, 18 June 2008 (UTC)

Thank you. That helps me understand it far more easily now. :) RingtailedFox • Talk • Contribs 12:22, 19 June 2008 (UTC)

Asteroid image and daft accusations

1. How can an article about an established fact lead off with an image of an hypothesis? (It is misleading - it misled me). If this image has to be in the article, it has to be attached to the relevant section, not stuck at the top of the page. 2. Given that at several points in the article it is clearly stated that the asteroid hypothesis is disputed - it is misleading to have the introduction state "Scientists theorize....". The intro must either read "Some scientists theorize.." or the statements throughout the article which refer to the debate must be removed. 90.231.2.252 (talk) 13:51, 25 July 2008 (UTC)

OK, it would be good to wait for some of the major contributors to the article to weigh into this, which they should do in the next few hours. Cheers, Casliber (talk · contribs) 14:13, 25 July 2008 (UTC)

I made an edit which moved the artist's rendering to the Impact event section, noting that it was in fact a rendering (and not a "reconstruction"), and that the matter was disputed. It seems inappropriate for an artist's imaginary rendering to dominate a scientific article, when there are perfectly suitable images to use. - Arcayne (^{cast a spell}) 15:35, 25 July 2008 (UTC)

What suitable images? Best to my knowledge, no one has a photo of a large-scale bolide impact on earth, so an artist's rendition does fine. OrangeMarlin ^{Talk• Contributions} 18:22, 5 August 2008 (UTC)

Why is it inappropriate to have an artist's rendering at the top of a scientific article? It's been done quite often; see Makemake (dwarf planet), etc. Firsfron of Ronchester 16:24, 25 July 2008 (UTC)

The point about any asteroid image being inappropriate is a good one - as 90.231.2.252 and Arcayne point out, the idea that the impact was wholly responsible for the extinction is only a hypothesis.

Most other extinction articles have the "Extinction of marine genera" graph at the top. Its biggest drawback is that it does not highlighted the extinction that the particular article is about - if desired I'll see what I can do about that. -- Philcha (talk) 16:29, 25 July 2008 (UTC)

It doesn't appear that Arcayne's point was that any asteroid image is inappropriate; rather that an artist's depiction is inappropriate, a point with which I disagree, as we can find these all over Wikipedia (and elsewhere). Nevertheless, The 'Extinction of marine genera' might be more suitable, as it places less emphasis on just one of the proposed causes of the extinction. Firsfron of Ronchester 16:39, 25 July 2008 (UTC)

Agree with Orangemarlin and Firsfron of Ronchester. I don't see why artist impressions should be inappropriate. Woodwalker (talk) 09:57, 6 August 2008 (UTC)

As OrangeMarlin pointed out, "no one has a photo of a large-scale bolide impact on earth, so an artist's rendition does fine".

However this discussion has not dealt much with the original point, repeated briefly by Arcayne's "that the matter was disputed", that bolide impact is only one of several hypotheses. In fact the K-T extinction may have been several processes of different durations but photo-finishing at the end of the K. -- Philcha (talk) 19:07, 6 August 2008 (UTC)

That's a valid argument of course. Not against using the artist impression, but against using it in a general way. The thing should not be at the top of the article (next to the intro), but it could be at the section about the impact theory. At the top a picture of the K-T-boundary in rocks (current version) or a fossil dinosaur (see nl:Krijt-Paleogeen-overgang, the Dutch version. Someone has placed a picture of a Tarbosaurus on top there) can be used, or something else, as long as it is NPOV. Woodwalker (talk) 10:00, 7 August 2008 (UTC)

Marine extinction intensity during Phanerozoic

%

Millions of years ago

(H)

K–Pg

Tr–J

P–Tr

Cap

Late D

O–S

The Cretaceous-Tertiary extinction event, labelled "End-K" here, is one of the most severe extinction events in this plot for marine genera.

I've proposed that the marine extinction graph be used at the top, as this would make it clear that the K-T extinction is not all about dinosaurs and was not the most severe.

Since I see the Dutch version is also careful to put the K-T extinction in perspective, the diagram might be useful there. The text in the diagram is really text, not part of the graphic, so it's really easy to edit it into Dutch. Give me a call if you'd like any help in converting the template - it's just a matter of translating the abbreviations and the titles of the articles to which they link. -- Philcha (talk) 11:57, 7 August 2008 (UTC)

If you want to make some moves and improving of the template, go for it. With regards to the dinosaurs, you do realize that just about anyone coming to read this article wants to read about dinos. As a matter of fact, one of the FA reviewers mentioned how disappointed she was to see there wasn't more dinosaur trivia in the article. Then she realize, like me, it wasn't all about the dinosaurs.OrangeMarlin ^{Talk• Contributions} 17:56, 11 August 2008 (UTC)

Thanks for the tip, see here. I made some clickable templates using other codes, for example at Paratethys, but this annotations template works even better. Woodwalker (talk) 09:44, 8 August 2008 (UTC)

Extinction and Endothermy

The fact that non-avian dinosaurs became suddenly extinct while crocodilians, their close relatives, survived the K-T boundary adds support to the theory of dinosaur's endothermy. Endothermic animals have a much faster metabolism than ectothermic ones, so that they need much more food to survive. Bigger animals also need more food for obvious reasons. Whatever the primary cause of the extinction was, it most probably passed through an interruption of food chains with the consequent starvation of animals. Some big size ectothermic groups such as crocodiles were survivors due to their especially low metabolic rate and food needs, while dinosaurs, as many other extinct species at the K-T event, probably died due to the food chain disruption described in the main article. Thus, extinction appears as another evidence supporting that at least some dinosaurs where endothermic animals. —Preceding unsigned comment added by 80.102.162.207 (talk) 17:16, 28 July 2008 (UTC)

I'm not sure you could make that conclusion just on survivability across the K-T boundary. I think one of the current theories is that burrowing animals were protected from environmental effects. Moreover, dinosaurs were in decline well before the K-T event. OrangeMarlin ^{Talk• Contributions} 18:15, 5 August 2008 (UTC)

"the survival of other endothermic animals, such as some birds and mammals, could be due, among other reasons, to their smaller needs of food related to their small size at the extinction epoch" is questionable as currently stated. Smaller endotherms need more food in proportion to their body weight, because they generally have a higher ratio of surface area to mass and therefore cool faster unless they "burn" more food. I suspect the survival of small endotherms is more likely due to the fact that smaller animals generally eat invertebrates, many of which feed on detritus rather than plants.

That raises a puzzle: which did no small non-avian dinos survive? Small predatory dinos ought to have been able to surive on the same invertebrates.

The idea that burrowing helped depends on the assumption that the Chixculub impact (or however you spell it) was the sole cause of the extinction and baked the whole earth either directly, by splattering it with red-hot ejecta, or indirectly via radiated heat from sub-orbital ejecta re-entering the atmosphere and glowing red-/white-hot. Last time I looked that idea was still controversial. Also burrowing would at best help only animals that were in their burrows at the time.

Is it now the scientific consensus that dinosaurs were in decline well before the K-T event? The article treats this a an issue that's still open. -- Philcha (talk) 15:05, 11 August 2008 (UTC)

We don't create our own conclusions. Cite comments. It's not our job to establish original research, it's only our job to write what has been published by others. I have no clue why small dinosaurs failed to survive. From what I've read, it's because the whole class was in decline, and maybe birds were just better able to adapt to environmental stress. BTW, it only takes a few members of the species to repopulate. If only 1% were burrowed at the time of the extinction event, that would be more than enough to start again. OrangeMarlin ^{Talk• Contributions} 16:47, 11 August 2008 (UTC)

One more comment. Before I wrote this article from the ground up, I just thought a comet hit the earth, dinosaurs died out, and that was that. After reading a lot of the articles, I don't think there is a firm consensus. I don't even think there is a solid consensus on what was the geographic event. I think there's a lot of ideas, a few theories, and some good research. I'll bet in a year, we will have to readjust some of this article (that's the cool thing about Wikipedia). Here's my one problem with everything being said, and this is pure speculation on my part--a comet of that magnitude would have release so much energy that it would have fried the earth. I would like to see someone tell me how a burrowing animal could survive that much heat. But this is my own original research, not anything based on anything. OrangeMarlin ^{Talk• Contributions} 16:53, 11 August 2008 (UTC)

I agree that "It's not our job to establish original research, it's only our job to write what has been published by others" - it simply surprises me that no journal articles have asked why no small predatory dinos survived. I searched in mid-2007 and found nothing. I also had some private correspondence with a paleo professor who made some suggestions, but he could not suggest citations.

IMO thinking things through for oneself does have value, by making one look to see if there's any published material on certain aspects of a topic. It usually works fairly well for me, although not in this case. For example it struck me that croc ectothermy was puzzling, considering that the evidence suggests dinos were certainly not like modern ectothermic land vertebrates; I kept looking and eventually found a paper that argued that crocs are secondarily ectothermic. Likewise on the origins of bird flight it struck me that a half-evolved wing would be a lousy gliding device (have you seen a bird's wing hyper-extended?) and I kept looking for citations on "ground up" vs "trees down" - and in the process found WAIR and why WAIR is unlikely. Ditto on Heilman's "birds from thecodonts" hypothesis.

Thinking things through also reduces the risk that an article might miss a question that an intelligent kid might ask - as in "Why has the King got no clothes?"

I also agree there's no firm consensus about either initial causes or killing mechanisms. That's why my main reservation shortly after the article reached FA was that it over-emphasised the bolide impact. My impression is that although the K-T extinction was less devastating than P-Tr, it was more complex. I could have cited stuff about that in autumn 2007, but no-one seemed interested. Dunno if I can find it again.

Doing justice to the complexity and to the range of variations on each of the causal theories (e.g. whether was there a global firestorm) would make already large article even larger - rough guess about 30%. Has anyone proposed splitting it per WP:SUMMARY? -- Philcha (talk) 17:33, 11 August 2008 (UTC)

I agree with your thinking process, which is why it's kept here in the discussion section. I too looked for data, and I have access to scholarly research tools. There are a few articles that speculate, but none have solid evidence. And aso for the bolide impact, please remember, once again, we can't synthesize research. The fact is that the vast weight of research in the K-T event centers around the bolide impact. Seriously, only one researcher, Keller, that is pushing the impact as being before the K-T event. There is also some research that is stating that the Deccan Traps were a result of the impact, and that caused the demise of the dinosaurs. That's a lot of tenuous links, and none of them have consensus as of yet. As of today, the consensus is that a bolide impact caused the K-T event (and there's a lot of evidence to confirm that). The article treats the other theories fairly, in an appropriate ratio to the weight out in the field. Since you and I lack Ph.D.'s in Paleontology, we probably won't be published with our ideas. But I like your thinking. I really would like to see some published theories as to why certain animals survived and certain others didn't. OrangeMarlin ^{Talk• Contributions} 17:53, 11 August 2008 (UTC)

I wasn't thinking of Keller's hypothesis that the impact was a few hundred KY before the K-T boundary, I was thinking mainly of Courtillot's research on the Deccan Traps. I remember reading a peer-reviewed article that said the bolide physically could not have caused the Deccan Traps eruptions - and IIRC the eruptions started before the consensus date for the impact.

I think it's prudent for Wikipedia articles to cover non-crackpot alternatives, and to avoid the impression of committing itself to any one theory, if possible. Remember how the theory of continental drift was scorned, despite very strong geological and paleo evidence? Or how in the 1970s and 1980s the dominant view of the Cambrian explosion was that all modern phyla appeared in the twinkling of a geological eye? Or the various daft theories about dinos that at various times enjoyed fairly wide support?

I suggested a while back that the K-T extinction article should take a more scientific approach by looking at the patterns of extinction in more detail, then considering possible killing mechanisms that would fit the patterns, before discussing causes. That would have at least 2 benefits: it would show readers how to think scientifically, which is badly needed considering the prevalence of anti-scientifc sentiment; and it would make it easier to adapt the article to new discoveries. -- Philcha (talk) 18:43, 11 August 2008 (UTC)

We can't do that, because we cannot create our own research. We can only present what is known and published, we can't "consider" mechanisms that haven't the backing of scientific consensus. The Deccan Traps are mentioned, and given the weight of research done for the bolide impact, a strict interpretation of WP:WEIGHT would say we gave it way too much undue weight. If you want to add more oomph to the Deccan Traps section, I would suggest you do so. But right now, it's speculative, just like 30 years ago Alvarez was ridiculed for his ideas about a bolide induced extinction event. And yes, there was initial reluctance about continental drift. But what you fail to note is that that the amount of scientific theories that have been thrown in the dustbin of history is huge. That's why we cannot write in the manner you suggest, because we cannot predict the future. What if someone writes that the Deccan Traps AND a bolide impact AND this AND that lead to the Dinosaur Extinction, but the K-T boundary is defined geologically as the bolide impact? Because we cannot predict the evolution of scientific research, we stick by the weight, NPOV, and etc. guidelines. In time, yes, this article will change. And we'll be there. But there isn't a consensus yet. And finally, yes, you and I can read the extinction patterns, but I would be reluctant to make adapt the article to fit what we see. It's just a listing right now, based on verifiable sources. Keep looking for that perfect article that brings it all together--then we can rewrite. OrangeMarlin ^{Talk• Contributions} 18:58, 11 August 2008 (UTC)

I wasn't suggesting we should "create our own research", I was suggesting an ideal structure for extinction articles. Admittedly there will some extinctions for which patterns of extinction / survivorship have been identified but have not yet led to deductions of killing mechanisms in the literature. If that's the case I'd be happy to state the patterns and, if supported, "so far no killing mechanisms have been identified".

"What if someone writes that the Deccan Traps AND a bolide impact AND this AND that lead to the Dinosaur Extinction, but the K-T boundary is defined geologically as the bolide impact?" No problem, as period boundaries are often rather arbitary, e.g. the base of the Cambrian.

What aspect of the Deccan Traps is speculative? They happened, AFAIK the date range is fairly well constrained, their size is fairly well known, and the admittedly larger Siberan Traps eruptions are the leading candidate for initial cause of the P-Tr extinction.

Not that I'm wedded to any hypothesis, in fact what I've seen about the complexity of the K-T patterns of extinction makes me strongly suspect some significant pieces are still missing. For me to write that into the article would be blatant WP:OR, but I'd be quite happy to present all that is known about about the patterns and let readers make up their own minds whether the hypotheses about killing mechanisms and initial causes explain the patterns. -- Philcha (talk) 19:49, 11 August 2008 (UTC)

←I've been working on some medical articles, so I forgot to get back here. Don't take that as my ignoring you. I guess I'm stating that the Deccan Traps involvement in the extinction event is still speculative, based on the lack of the breadth and depth of articles that we might find for the bolide impact. I saw an interesting show on Discovery Channel or the National Geographic network (can't remember which) that showed how a bolide impact might cause huge volcanic activity at the opposite side of the planet. They had a name for it, but it escapes me now. I would be concerned if we used a TV show as a reference, but maybe we can find the researcher who is proposing this mechanism and quote it here. As for letting the reader make up their mind--well, I'm not sure that's our goal. We don't let fringe theories in here, and some of the theories that you propose to add have moved from fringe (not the crazy fringe, more of the fringe of science) to not-quite-mainstream. We should give weight only at that level. OrangeMarlin ^{Talk• Contributions} 17:25, 18 August 2008 (UTC)

Please remind me to return to this. Right now I'm involved in a GA review (chess) plus articles relating to the Cambrian explosion (one of which is up for GA). But last time I edited "Cretaceous–Tertiary extinction event" I had a fair idea of the literature, including the "impact caused the Deccan eruptions theory" - IIRC that was considered physically impossible for a bolide of the size estimated for Chixculub, and did not fit the chronological evidence. -- Philcha (talk) 17:52, 18 August 2008 (UTC)

First sentence of extinction patterns

This "During the Maastrichtian stage of the Cretaceous, there was already a progressive decline in biodiversity prior to the ecological crisis indicated by the K–T boundary." and the ref to MacLeod et al seems to be based on out of date research. This paper [1] is a more recent examination of the Hell's Creek formation data and casts doubt on whether megafauna diversity was actually in decline prior to the K-T. Unless something newer that I've missed has come along shouldn't this sentence be removed? Kbs666 (talk) 06:12, 25 August 2008 (UTC)

That paper seems to refute the claim that dinosaur abundance was down, not that dinosaur diversity was down. There is a difference: abundance is based on numbers, while diversity is all about the types of dinosaurs found in that formation. MacLeod isn't the only author who has reported the decline in diversity; I do know Dodson reported it, too. Firsfron of Ronchester 05:41, 29 August 2008 (UTC)

This [2] says otherwise. Kbs666 (talk) 21:57, 29 August 2008 (UTC)

You're pulling one paper. I'm sure there are others, and we can take a look at them. The MacLeod reference is a wonderful review paper, which ranks highest on the list of reliable sources. If you analyze the paper in detail, you'll see that he's "estimating" the diversity in the late Cretaceous. He uses a mathematical model for that estimate. This is interesting, but it is speculative. In essence, and I may be exaggerating, he's saying, "I think that there was not a decline in diversity, and I'm not going to prove it by the number of fossils found, but on an estimate of the number of fossils unfound." I'm not sure I get it. OrangeMarlin ^{Talk• Contributions} 23:11, 29 August 2008 (UTC)

I can present more. I can't read it, can't read technical Spanish, but I know there is another paper indicating no loss of diversity in the pre boundary terrestrial Spanish site. MacLeod is simply outdated. Kbs666 (talk) 00:59, 30 August 2008 (UTC)

Possibly on this one point, but one or two references don't outdate an article. In fact, there are literally thousands of articles from the 1940's that are considered reliable sources for many articles. We can't give undue weight. OrangeMarlin ^{Talk• Contributions} 04:23, 30 August 2008 (UTC)

I'm not giving undue weight to any source. The article stated, in encyclopedic voice, that a reduction in species diversity occured prior to K-T. That was the consensus in 1996 as the MacCleod paper shows. However since then other studies have come out casting doubt on the issue. I simply removed the subject entirely. If you prefer we can go to something where "This paper says x and this paper says Y" but simply removing the statement seemed simpler. Kbs666 (talk) 04:58, 30 August 2008 (UTC)

Well, I wouldn't do that until you get some consensus around here. You have brought no papers to the table that convince me or other editors of a change in sentiment. Again, I'm not getting the "1996" argument. Darwin published in the 1800's and most of his viewpoints on evolution still stand. Anyways, if there are some reasonable sources that support that particular hypothesis going away, let's do it. For now, this is a Featured Article, and we should be judicious in changing key ideas. OrangeMarlin ^{Talk• Contributions} 05:04, 30 August 2008 (UTC)

What's not to get? MacCleod was published in 1996. Since then multiple papers have been published that cast doubt on the earlier paper's conclusions. A paper that is the consensus when it is published doesn't always stay the consensus. Although right now I don't think there is a consensus either way. And just to be clear most of Darwin's viewpoints on evolution do not still stand. The modern synthesis built on his original idea but Darwin had no concept of genetic drift and many leading researchers on the drift versus natural selection issue think drift is the more important mechanism. Kbs666 (talk) 06:52, 30 August 2008 (UTC)

Dodson's 2006 paper refutes his earlier observations. I am convinced by your link, and agree that the paragraph in question will need rewording before it should be added back in. However, I do not think the paragraph should be left out altogether, as it's a theory that is bound to be resurrected (or reinserted by a later editor), and it's still topical to the article. The paragraph should discuss LK dinosaur diversity, and include the current opposing viewpoints. As OM says, this is a FA, and it's supposed to represent comprehensive coverage of the subject. Firsfron of Ronchester 05:30, 30 August 2008 (UTC)

I'd just be careful drawing too much out of one set of formations (especially when there may be additional factors are at work: one, the Dinosaur Park Formation has traditionally been presented as a monolith of dinosaurs, where everything known from it lived at the same time, but more recent work has shown that there were multiple time-successive faunal assemblages; and two, the DPF was closer to the shoreline and thus would have had more varied habitats, whereas the Hell Creek and correlatives include quite a bit of territory that was further away from the intercontinental sea and would have been less variable, allowing less specialization. Perhaps a more apt comparison would be the Two Medicine Formation and the Hell Creek Formation.). J. Spencer (talk) 15:15, 30 August 2008 (UTC)

"Non-avian dinosaurs"

I've undone these good-faith edits by 75.36.146.76. AFAIK the consensus we reached at Talk:Dinosaur was that "non-avian dinosaurs" should be used whenever there was risk of confusion between the popular conception of dinos (Tyrannosaurus, Triceratops, Edmontosaurus, etc.) and animals that are more closely related to modern birds than to any of the "popular" dinos. 75.36.146.76 removed "non-avian" and then, because phylogenetically birds are dinos, had to make other changes that I think would confuse readers with little background knowledge. This makes it difficult to describe the critters whose extinction left the field open for mammals. I think we need to agree on phrasing, and have invited 75.36.146.76 to contribute. --Philcha (talk) 11:25, 22 November 2008 (UTC)

"Impact event causing vulcanism"

Didn't see anywhere how a impact event could of caused the vulcanism. Since both Mars and mercury show huge amounts of vulcanism after impact events. Should put in here how the impact on one side planet could of caused the vulcanism on the other. Since the concusion waves meet up on other side planet. The whole Deccen Traps theory isn't contrary to impact causing extinction since impact could of caused em.69.154.136.154 (talk) 06:22, 16 December 2008 (UTC)

We need reliable sources for anything we add. OrangeMarlin ^{Talk• Contributions} 07:36, 16 December 2008 (UTC)

Mars and Mercury are not the Earth. First it's bigger, second its composition is different. Apart from that, the impact basins on the Moon associated with large scale volcanism were at a time when the Moon was still very hot and, if I remember well, the impacting objects are modeled to have been way larger than the K-T-impactor. So I agree with OrangeMarlin: this needs reliable sources. Woodwalker (talk) 07:46, 16 December 2008 (UTC)

Inclusion in Category:Mammals

OrangeMarlin: i don't see it. Category:Dinosaurs makes sense, as it was the end of the group, by and large; plus, the entry *is* part of the Dino WP; so fair enough. but the KT event wasn't the "Start of mammals", as you say in your revert. several taxa "took off" after this event; should we include this entry w/in *all* categories so tangentially related? is that really helpful? - Μετανοιδ (talk, email) 03:59, 4 March 2009 (UTC)

Other theory

It seems important to me to advance a hypothesis that never appears, the iridium toxicological hypothesis. It is in my opinion the only one that permits to understand why mainly the terrestrial, marine and aerial big or small dinosaurs disappeared on the whole planet. Jacques Roques april 2009 —Preceding unsigned comment added by 88.167.228.4 (talk) 10:47, 12 April 2009 (UTC)

Which "toxicological hypothesis"? If you mean alkaloid poisoning caused by flowering plants, that was discarded long ago because the earliest flowering plant fossils are from about 125 million years ago in the early Cretaceous, and dinos surviced for about another 60 M yrs. In any case the K-T extinction isn't all about dinos - ecologically the extinction of reef-forming rudist bivalves was at least as significant, and ammonites also perished at the end of the Cretaceous (but may have been in steep decline already). --Philcha (talk) 11:53, 12 April 2009 (UTC)

The suppressed article was :

"A simpler and verifiable theory is never advanced concerning the disappearance of the dinosaurs. Yet it has the advantage to explain why mainly a species composed of big and small terrestrial, aerial and marine (but endowed of lungs) animals has been eradicate. The mammals, the reptiles, fishes, without speaking of the plants and bugs, arthropods, etc. endured the shock apparently better, even if some have certainly also disappeared. The theory of the arctic-cold weather is not more satisfactory. Was this cold weather as intense to the equator? Moreover one knows today that there were dinosaurs which did not fear it, which cancels this theory definitively. On the other hand one can be astonished to don’t see stated as first causes, the toxicological assumption. It is however proven that the iridium that one generally associates to a meteorite fall a few thousands of years before in the peninsula of Yucatan, covered the whole earth. It is a heavy metal and its salts are highly toxic. It is possible that starting from some concentration and by taking account of a different sensitivity to the poison according to species', only certain types of animals disappeared. Whether they are terrestrial, aerial or marine, they all had to breathe and while consuming massively (what supposes that they were warm-blooded reptiles, these animals having more food’s needs that the cold-blooded animals) plants or already poisoned animals, they increased the iridium concentration in their body. Iridium is perhaps also a poison which intervenes on the fertility, which would explain why the extinction spread out over a certain number of years. Only the less receptive animal species to the iridium could have survived” —Preceding unsigned comment added by 88.167.228.4 (talk) 16:22, 12 April 2009 (UTC)

And the source for this is...? We don't include original research. Vsmith (talk) 16:52, 12 April 2009 (UTC)

On the K-T boundary there is a concentration of iridium many times greater than normal (30 times and 130 times background in the two sections originally studied by Luis Alvarez) Finely divided iridium powder can be hazardous to handle, as it is an irritant and the toxicity of iridium compounds and soluble salts, such as the iridium halides, due to elements other than iridium or due to iridium itself is established. —Preceding unsigned comment added by 88.167.228.4 (talk) 18:13, 12 April 2009 (UTC)

(a) Where are the citations?

(b) "the toxicity of iridium compounds ... is established" - not by tests on dinosaurs. More likely by tests on lab rats, which are mammals. Hmmm. Philcha (talk) 18:41, 12 April 2009 (UTC)

You are right. It would be necessary to make an analysis of the effects of the poisoning by the iridium and its compounds according to the used doses, on the mammals and the birds to verify this hypothesis —Preceding unsigned comment added by 88.167.228.4 (talk) 21:06, 12 April 2009 (UTC)

bugs and bug-eaters

From the descriptions of extinction patterns, it seems clear to me that terrestrial animals that ate insects (mammals, frogs, salamanders) were relatively unaffected by the splat. Many folivorous insects would have gone extinct, but the saprophages would have been in heaven. I envision a sky glutted with carrion-flies and their ilk. We mammals thank them! —Preceding unsigned comment added by 141.223.141.143 (talk) 13:01, 12 April 2009 (UTC)

If you could find some reliable sources for this vision from Dante or Hieronymus Bosch, several mammals would thank you. --Philcha (talk) 13:21, 12 April 2009 (UTC)

More post Cretaceous dinosaur survival

Is this anything? http://www.telegraph.co.uk/science/dinosaurs/5256574/Dinosaurs-survived-in-a-remote-lost-world-for-half-a-million-years-before-extinction.html FunkMonk (talk) 15:14, 14 September 2009 (UTC)

Based on article by Fassett (2009) in Palaeontologia Electronica. The same mag subsequently published some harsh criticism of the dating and suggests the fossils were reworked. --Philcha (talk) 15:47, 14 September 2009 (UTC)

megaflora

What is it? Is it defined somewhere in wikipedia? Should it be used if it is not a well understood word?   Thanks, Daniel.Cardenas (talk) 19:44, 7 October 2009 (UTC)

Should the dating be changed?

The date of 65.5 million years ago in the first sentence of this article is not footnoted and it may no longer be correct. In the article on Argon-argon dating there is a section titled Recalibration, part of which reads: Thus the K-T Extinction (when the dinosaurs died out) - previously dated at 65.0 or 65.5 million years ago - is more accurately dated to 66.0 Ma. —Preceding unsigned comment added by 208.73.31.50 (talk) 18:36, 6 November 2009 (UTC)

Role of acid rains

I'm in the process of translating the article to French, and the text of the article on this particular point doesn't sound very logical to me. First we're told acid rains were probably playing a minor role as frog survived. A bit further the article says that they destroyed plants and killed plankton, mollusks and others and later that since the impactor landed deeper than thought earlier, acid rains played a bigger role. I have the impression that this is just the outcome of the additional of recent research results and would be grateful if somebody would clarify this point. --Anneyh (talk) 23:13, 6 February 2010 (UTC)

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