Polyptychodon
{{short description|Genus of pliosaurid plesiosaur from the Cretaceous period}}
{{Italic title}}
{{Taxobox
|name = Polyptychodon
|fossil_range = Late Cretaceous, {{fossil range|101|89.3}}
|image = Polyptychodon.jpg
|image_width = 250px
| image_caption = P. interruptus jaw with tooth
|regnum = Animalia
|phylum = Chordata
|classis = Sauropsida
|ordo = {{extinct}}Plesiosauria
|subordo = {{extinct}}Pliosauroidea
|familia = {{extinct}}Pliosauridae
| subfamilia = {{extinct}}Brachaucheninae
|genus = {{extinct}}Polyptychodon
|genus_authority=Owen, 1841{{cite book|author=Owen R.|year=1841|title=Odontography|publisher=Hippolyte Baillière|location=London|page=655}}
|binomial = {{extinct}}Polyptychodon interruptus
| binomial_authority = Owen, 1841
| subdivision_ranks = Other species
| subdivision =
- {{extinct}}P. patagonicus?
Ameghino, 1893
}}
Polyptychodon (meaning 'many-folded tooth') is a genus of pliosaurid found in Middle-Late Cretaceous marine deposits in southern England, France and Argentina. It has been considered a nomen dubium in a 2016 review.
History of discovery
File:Polyptychodon interr2DB.jpg
The type species, P. interruptus is known from an isolated tooth from the Late Cretaceous Chalk Group of southern England. Owen described a second nominal species of the genus, P. continuus, from an isolated tooth collected in the Hythe Formation of Maidstone, Kent. (The macronarian sauropod Dinodocus was mistakenly thought to be conspecific with P. continuus before it was correctly recognized as a dinosaur and not a plesiosaur.)
Numerous pliosaurid teeth and vertebrae from England and eastern France have been previously assigned to Polyptychodon, including isolated vertebrae from France which were misidentified as a sauropod.{{cite journal|author=Buffetaut E, Colleté C, Dubus B, Petit J-L.|year=2005|title=The "sauropod" from the Albian of Mesnil-Saint-Père (Aube, France): a pliosaur, not a dinosaur|journal=Association Géologique Auboise, Bulletin Annuel, Sainte-Savine|volume=26|pages=3–8}} Comparison between Albian-age isolated vertebrae from marine deposits in France and Kronosaurus suggested a size of approximately {{convert|7|m|ft}} for a Polyptychodon-like brachaucheniine pliosaurid. However, a 2016 re-evaluation found Polyptychodon and its types species to be dubious, and that numerous remains from the Chalk Group in England that had been referred to the genus most likely represent different species of plesiosaurs, with some teeth possibly being referable to Polycotylidae.{{cite journal|author=Madzia D.|year=2016|title=A reappraisal of Polyptychodon (Plesiosauria) from the Cretaceous of England|journal=PeerJ |volume=4 |pages=e1998 |doi=10.7717/peerj.1998 |pmid=27190712 |pmc=4867712 |doi-access=free }} Similar fossils of pliosaurs were found also in Czech Republic.{{Cite web|url=http://dinosaurusblog.com/2015/07/13/druhohorni-plazi-v-cechach-ii/|title = Druhohorní plazi v Čechách II|date = 13 July 2015|lang=cs|trans-title=Mesozoic reptiles in Bohemia, part 2}}
The species Polyptychodon patagonicus (Ameghino, 1893), based on crocodile teeth discovered in Argentina, shares the same genus name. According to a 2010 study, P. patagonicus is a nomen vanum and a nomen dubium.{{cite journal|author1=J. P. O'Gorman|author2=A. N. Varela|year=2010|title=The oldest lower Upper Cretaceous plesiosaurs (Reptilia, Sauropterygia) from Southern Patagonia, Argentina|journal=Ameghiniana|volume=47|issue=4|pages=447–459|doi=10.5710/AMGH.v47i4.3 |s2cid=129812539 |url=http://sedici.unlp.edu.ar/handle/10915/95720 |editor1=P. Mannion|editor2=J. Tennant}}
File:Polyptychodon skull parts.jpg
Polyptychodon hudsoni (holotytpe, SMU 60313) was described from the Turonian-age Eagle Ford Formation of Dallas, Texas.{{cite journal|author=Welles SP, Slaughter BH|year=1963|title=The first record of the plesiosaurian genus Polyptychodon (Pliosauridae) from the New World|journal=Journal of Paleontology|volume=37|issue=1|pages=131–133}}{{cite web|url=http://texashistory.unt.edu/ark:/67531/metapth28009/|title=Plesiosaur Unearthed During Preliminary Excavation for the Dallas-Fort Worth International Airport}} It probably belongs to a different genus.{{cite journal |last1=Madzia |first1=Daniel |last2=Sachs |first2=Sven |last3=Lindgren |first3=Johan |title=Morphological and phylogenetic aspects of the dentition of Megacephalosaurus eulerti, a pliosaurid from the Turonian of Kansas, USA, with remarks on the cranial anatomy of the taxon |journal=Geological Magazine |date=2019 |volume=156 |issue=07 |pages=1201–1216 |doi=10.1017/S0016756818000523}}
See also
{{Portal|paleontology}}
References
{{Reflist}}
External links
- [https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=36507 Polyptychodon] in the Paleobiology Database
{{Plesiosauria|Pliosauroidea}}
{{Taxonbar|from=Q572528}}
Category:Late Cretaceous plesiosaurs of Europe
Category:Cenomanian genus first appearances
Category:Turonian genus extinctions
Category:Fossil taxa described in 1841