Greene Formation is a geologic formation located in Ohio, West Virginia and Pennsylvania that has been dated to the Seymouran Land-Vertebrate Faunachron of the Early Permian. It is the youngest formation within the Dunkard Group, putting it right above the Washington Formation stereographically.[1]

Greene Formation
Stratigraphic range: Early Permian,
Kungurian
TypeFormation
Unit ofDunkard Group
OverliesWashington Formation
Thickness200 metres (660 ft)
Lithology
Primaryshale, mudstone, sandstone
Otherlimestone, coal
Location
Region Ohio West Virginia Pennsylvania
Country United States
Type section
Named forGreene County

Description

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The geology of the Greene Formation mostly contains a mix of shaly sandstone and shale with facies containing limestone and coal.[2] Though the currently preserved thickness of the formation is around 200 meters, the top of the formation has been eroded away, making it impossible to tell the full depth of the formation.[1]

Paleobiota

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Chondrichthyes

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Genus Species Notes Image
Barbclabornia[3] B. luedersensis A large xenocath shark from the Permian of North America. Due to the shape of the dentition, it is believed that it would have been a filter-feeder comparable to whale and basking sharks.[4]  

Dipnoi

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Genus Species Notes Image
Sagenodus[5] S. sp A wide-spread genus of lungfish that shows a transitional phase between the Devonian and Post-Paleozoic lungfish structures.[6]Found at the Clark Hill locality, in the same quarry as Ctenospondylus and Trimerorhachis.[5]  

Lepospondyli

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Genus Species Notes Image
Brachydectes B. sp A small lysorophian that was orginally assigned to the genus Lysorophus though was later reassigned to the genus Brachydectes.[1]  
Diploceraspis[7] D. burkei A diplocaulid and most well-known Nectridean from the formation, it's been suggested that the shape of the head caused by the extreme lengthening of the tabular and squamosal bones of the skull may be convergent to those found in Diplocaulus rather than from a common ancestor.[1]  
Lysorophus[1] L. dunkardensis A small lysorophian with a serpent-like body and short limbs, it's questioned if the genus is valid though L. dunkardensis is still currently assigned to the genus.[1]
 
Megamolgophis[1] M. agostinii A very large lysorophian estimated at a length of 1.3 meters. Like other lysorophians, the animal's limbs were extremely small but unlike others, Megamologophis's vertebral centra were comparatively complicated.[8]

Synapsida

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Genus Species Notes Image
Ctenospondylus[1] C. ninevehensis A large sphenacodontid with sorter neural spines than seen in Dimetrodon, the animal is also an index taxa for the Seymouran LVF.[1]  
Edaphosaurus[8] A large and widespread edaphosaurid that had spines coming off on the sides of its neural arches, a characteristic of the family. Just like seen in formations in Texas, there is a transition in the species between earlier and later strata of the group. Between the Washington and Greene formations, a shift from E. cf. E. boanerges to E. cf. E. cruciger.[1]
 
Ophiacodon[1] O. cf. O. uniformis A large and late surviving ophiacodontid known from 10 vertebrae, along with an incomplete left forelimb.[9]  

Temnospondyli

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Genus Species Notes Image
Eryops[8] E. cf. E. megacephalus A large eryopid that is common throughout the Dunkard Group that looks most similar to E. megacephalus though this would make it the only member of the family to come from the group.[1]
 
Trimerorhachis[5] T.sp A medium-sized dvinosaurid with small-poorly ossified limbs, there's not much known about the specimen found in the Greene Formation, only that it was found in the same quarry as the holotype of Ctenospondylus ninevehensis.[5][10]
 
Zatrachys[11] Z. cf. Z. serratus A zatrachydid known from a fairly complete skull, though it can't be assigned to a specific species within the genus. This is mainly because of some inconsistences in the sutural lines of the skull table when comparing them to those found in New Mexico.[11]  

Tetrapodamorpha

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Genus Species Notes Image
Ambedus[12] A. pusillus A small tetrapodamorph originally classified as a diadectid though later studies have since concluded that the features in the teeth that placed the animal within the group were a result of convergent evolution. It's unknown if Ambedus is even within diadectimorpha.[13]

Plants

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Genus Species Notes Image
Alethopteris[14] ?A. sp
Autunia[15] A. conferta
A. naumannii
Lepidophylloides[14] L. sp
Lodevia[15] L. oxydata
Pecopteris[14] ?P. sp
Rhachiphyllum[15] R. schenkii
Sigillaria[14] S. brardii
S. sp.

Paleoenvironment

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The paleoenvironment of the Greene Formation was a lake in a seasonal dry area shown by the large amounts of vertisols, especially when compared to earlier formations in the group. Around the lake there would have been both seed ferns and lycophytes though much fewer in numbers than earlier in the Dunkard Group; being shown by the steady decrease in the amount and depth of coal layers within the group. [15]The overall trends in the paleosols of the Greene Formation are seen in the general transition to more arid climates from the Pennsylvanian to Middle Permian.[16]

References

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  1. ^ a b c d e f g h i j k l Lucas, Spencer G. (2013). "Vertebrate biostratigraphy and biochronology of the upper Paleozoic Dunkard Group, Pennsylvania–West Virginia–Ohio, USA". International Journal of Coal Geology. 119: 79–87. Bibcode:2013IJCG..119...79L. doi:10.1016/j.coal.2013.04.007. ISSN 0166-5162.
  2. ^ Oil and gas fields of Greene County, PA (Report). US Geological Survey. 1907. doi:10.3133/b304.
  3. ^ Johnson, Gary D. (2008-04-22). "Dentitions of Barbclabornia (new genus, Chondrichthyes: Xenacanthiformes) from the Upper Palaeozoic of North America". Fossil Record. 6 (1): 125–146. doi:10.1002/mmng.20030060106. ISSN 1435-1943.
  4. ^ Hampe, O.; Ivanov, A. (2007-08-01). "Bransonelliformes – a new order of the Xenacanthimorpha (Chondrichthyes, Elasmobranchii)". Fossil Record. 10 (2): 190–194. Bibcode:2007FossR..10..190H. doi:10.5194/fr-10-190-2007. ISSN 2193-0074.
  5. ^ a b c d Berman, David S. (1978-12-01). "Ctenospondylus ninevehensis, a new species (Reptilia, Pelycosauria) from the Lower Permian Dunkard Group of Ohio". Annals of the Carnegie Museum. 47: 493–514. doi:10.5962/p.215827. ISSN 0097-4463.
  6. ^ Schultze, H.-P.; Chorn, J. (1997). "The Permo-Carboniferous genus Sagenodus and the beginning of modern lungfish". Contributions to Zoology. 67 (1): 9–70. doi:10.1163/18759866-06701002. ISSN 1383-4517.
  7. ^ May, William J.; Hall, Joseph D. (2016). "First Occurrence of the Diplocaulid GenusDiploceraspisfrom the Wellington Formation (Lower Permian) of Northern Oklahoma". Transactions of the Kansas Academy of Science. 119 (2): 193–199. doi:10.1660/062.119.0209. ISSN 0022-8443.
  8. ^ a b c Romer, Alfred Sherwood (1952-09-22). "Late Pennsylvanian and Early Permian vertebrates of the Pittsburgh-West-Virginia region". Annals of the Carnegie Museum. 33: 47–112. doi:10.5962/p.215221. ISSN 0097-4463.
  9. ^ Stephens, John J. (1964). "Ophiacodon from Ohio". Ohio Journal of Science (Ohio Academy of Science). 64 (3): 217–220.
  10. ^ Milner, Andrew R.; Schoch, Rainer R. (2013-10-01). "Trimerorhachis (Amphibia: Temnospondyli) from the Lower Permian of Texas and New Mexico: cranial osteology, taxonomy and biostratigraphy". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 270 (1): 91–128. doi:10.1127/0077-7749/2013/0360. ISSN 0077-7749.
  11. ^ a b Urban, Michael; Berman, David S. (2007). "First Occurrence of the Late Paleozoic Amphibian Zatrachys Serratus (Temnospondyli, Zatrachydidae) in the Eastern United States". Annals of Carnegie Museum. 76 (3): 157–164. doi:10.2992/0097-4463(2007)76[157:footlp]2.0.co;2. ISSN 0097-4463.
  12. ^ Kissel, Richard A.; Reisz, Robert R. (2004-12-31). "Ambedus pusillus, new genus, new species, a small diadectid (Tetrapoda: Diadectomorpha) from the Lower Permian of Ohio, with a consideration of diadectomorph phylogeny". Annals of the Carnegie Museum. 73 (4): 197–212. doi:10.5962/p.215153. ISSN 0097-4463.
  13. ^ Bulanov, V. V. (2023-03-01). "The Discovery of Diadectomorph Tetrapods in the Lower Permian of Eastern Europe". Палеонтологический журнал (2): 88–99. doi:10.31857/s0031031x2302006x. ISSN 0031-031X.
  14. ^ a b c d Berryhill, Henry L.; Schweinfurth, Stanley P.; Kent, Bion H. (1971). "Coal-bearing Upper Pennsylvanian and Lower Permian rocks, Washington area, Pennsylvania". USGS Report: 2. Bibcode:1971usgs.rept....2B. doi:10.3133/pp621. ISSN 2330-7102.
  15. ^ a b c d DiMichele, William A.; Kerp, Hans; Sirmons, Roberta; Fedorko, Nick; Skema, Viktoras; Blake, Bascombe M.; Cecil, C. Blaine (2013). "Callipterid peltasperms of the Dunkard Group, Central Appalachian Basin". International Journal of Coal Geology. 119: 56–78. Bibcode:2013IJCG..119...56D. doi:10.1016/j.coal.2013.07.025. ISSN 0166-5162.
  16. ^ Cecil, C. Blaine (2013). "An overview and interpretation of autocyclic and allocyclic processes and the accumulation of strata during the Pennsylvanian–Permian transition in the central Appalachian Basin, USA". International Journal of Coal Geology. 119: 21–31. Bibcode:2013IJCG..119...21C. doi:10.1016/j.coal.2013.07.012. ISSN 0166-5162.