Talk:Acanthopholis

Acanthopholis lived around 140 Mio years ago, thats the Berriasian age, not albian! —Preceding unsigned comment added by 77.183.21.101 (talk) 12:27, August 30, 2007 (UTC)

Are you sure about that? It's from the Cambridge Greensand, which is in the Apti-Ceno range. J. Spencer 13:11, 30 August 2007 (UTC)

Hold up ---- the type species of Acanthopholis is from the Lower Chalk Group, but the referred species are from the Cambridge Greensand. They were probably reworked from the Gault Clay (the fact that the remains of Anoplosaurus were assigned to a single individual and found in the same locality suggests that Anoplosaurus may come from the Gault Clay rather than the Cambridge Greensand as pointed out by Pereda-Suberbiola and Barrett 1999). 68.4.28.33 (talk) 03:27, 20 July 2012 (UTC)Vahe Demirjian

Reference addition

Pereda-Suberbiola and Barrett (1999) demonstrated the undiagnostic nature of Acanthopholis horridus and declared it a nomen dubium, assigning it to Nodosauridae indeterminate based on characters cited as diagnostic for Nodosauridae by Coombs and Maryanska (1990). In addition, Pereda-Suberbiola and Barrett (1999) considered the remaining species of Acanthopholis as nomina dubia: Acanthopholis macrocercus, A. stereocercus, A. eucercus, and A. platypus. A. macrocercus and A. stereocercus were demonstrated to be chimeric, being based on ankylosaur and ornithopod material, A. eucercus was assigned to Ornithischia indeterminate, and A. platypus was found to be a chimera of anklyosaur and sauropod material. The assignment of Acanthopholis to Nodosauridae, however, remains suspect, for recent developments in ankylosaur phylogeny (Carpenter, 2001; Kirkland, 1998) have placed polacanthids closer to ankylosaurids than to nodosaurids and therefore the characters that Coombs and Maryanska (1990) used to diagnose Nodosauridae are untenanble. It is best to place Acanthopholis as an ankylosaur of uncertain affinities.

Kirkland, J.I. 1998. A polacanthine ankylosaur (Ornithischia: Dinosauria) from the Early Cretaceous (Barremian) of Eastern Utah. Pp 271-281 in, S.G. Lucas, J.I. Kirkland and J.W.Estep (eds.), Lower and Middle Cretaceous Terrestrial Ecosystems. New Mexico Museum of Natural History and Science Bul. 14.

Carpenter, K. 2001. Phylogenetic Analysis of the Ankylosauria. Pp. 455-483 in K. Carpenter (ed.). The Armored Dinosaurs. Indiana University Press, Bloomington.

Coombs, W., and T. Maryanska. 1990. Ankylosauria. Pp. 456-483 in D. Weishampel, P. Dodson and H. Osmolska (eds.), The Dinosauria. University of California Press, Berkeley.

Suberbiola, X.-P., and Barrett, P.M. (1999). A systematic review of ankylosaurian dinosaur remains from the Albian of England. Special Papers in Palaeontology 60:177-208.68.4.61.237 (talk) 22:27, 24 September 2010 (UTC)Vahe Demirjian

Species list

Seeley (1869) states that his new species were not intended to be described species, so they qualify as nomina nuda under the provisions of Article 12 of the ICZN Code. This means that Acanthopholis macrocercus is a nomen nudum for Syngonosaurus macrocercus, while the species Acanthopholis platypus and A. stereocercus were described as new species in detail by Seeley in his 1871 and 1879 publications respectively. In this case, Syngonosaurus macrocercus is known only from the syntype vertebrae (which belong to an ornithopod), taking into account the fact that Seeley doubted whether the armor was found in association with the syntypes of Syngonosaurus. For clarity, Acanthopholis eucercus was actually described in the 1879 paper by Seeley, not the 1869 catalog (where it is only referred to as 'reptile-dinosaur'). Thus, Syngonosaurus is an indeterminate ornithopod (since Seeley did not consider the ankylosaur armor to be the same individual as the syntype vertebrae), while A. eucercus, A. platypus, and A. stereocercus are still based on composite syntype series with no lectotype designated. (As a side note, the syntype metatarsus may someday be designated the lectotype of A. platypus because the original diagnosis for that species was based on characters of the foot and Le Loeuff [1993] notes that the Cambridge Greensand sauropod Macrurosaurus is a composite of two separate sauropod taxa, one being a titanosaur.)

Le Loeuff J. 1993. — European titanosaurids. Revue de Paléobiologie, volume spécial 7 : 105-117. 68.4.28.33 (talk) 03:55, 20 July 2012 (UTC)Vahe Demirjian

Are there any papers dealing specifically with this issue? If not, it would be original research. Capra walie (talk) 23:19, 6 August 2014 (UTC)

Cambridge Greensand

Remains were found in the Cambridge Greensand: is this not technically the base of the Upper Cretaceous? And so should not the taxobox etc be adjusted? That would suggest a date of about 94 mya for the fossils (no dates are given on the Cambridge Greensand page, but that would seem about right). Since there seems no doubt that the genus survived the Lower Cretaceous, the intro and taxobox should reflect that. Macdonald-ross (talk) 11:18, 29 September 2018 (UTC)