polycotylidae
{{Short description|Extinct family of reptiles}}
{{Automatic taxobox
| name = Polycotylids
| fossil_range = Early - Late Cretaceous, {{fossil range|113|72}}
| image = Martinectes transparent background.png
| image_upright = 1.15
| image_caption = Martinectes in the Rocky Mountain Dinosaur Resource Center
| taxon = Polycotylidae
| authority = Williston, 1909
| subdivision_ranks = Genera
| subdivision =
- {{extinct}}Edgarosaurus
- {{extinct}}Manemergus
- {{extinct}}Mauriciosaurus
- {{extinct}}Piratosaurus?
- {{extinct}}Rarosaurus?
- {{extinct}}Thililua
- {{extinct}}Occultonectia{{cite journal |author1=V. Fischer |author2=R. B. J. Benson |author3=P. S. Druckenmiller |author4=H. F. Ketchum |author5=N. Bardet |year=2018 |title=The evolutionary history of polycotylid plesiosaurians |journal=Royal Society Open Science |volume=5 |issue=3 |pages=172177 |doi=10.1098/rsos.172177 |pmid=29657811 |pmc=5882735 |bibcode=2018RSOS....572177F }}
- {{extinct}}Plesiopleurodon
- {{extinct}}Sulcusuchus
- {{extinct}}Palmulasaurinae
- {{extinct}}Pahasapasaurus
- {{extinct}}Palmulasaurus
- {{extinct}}Polycotylinae
- {{extinct}}Eopolycotylus
- {{extinct}}Georgiasaurus
- {{extinct}}Polycotylus
- {{extinct}}Scalamagnus
- {{extinct}}Serpentisuchops
- {{extinct}}Trinacromerum
- {{extinct}}Dolichorhynchia{{Cite journal |last1=Clark |first1=Robert O. |last2=O’Keefe |first2=F. Robin |last3=Slack |first3=Sara E. |date=2023-12-24 |title=A new genus of small polycotylid plesiosaur from the Upper Cretaceous of the Western Interior Seaway and a clarification of the genus Dolichorhynchops |url=https://www.sciencedirect.com/science/article/pii/S0195667123003403 |journal=Cretaceous Research |volume=157 |pages=105812 |doi=10.1016/j.cretres.2023.105812 |issn=0195-6671|url-access=subscription }}
- {{extinct}}Dolichorhynchops
- {{extinct}}Martinectes
- {{extinct}}Unktaheela
}}
Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae. They are known as false pliosaurs. Polycotylids first appeared during the Albian stage of the Early Cretaceous, before becoming abundant and widespread during the early Late Cretaceous. Several species survived into the final stage of the Cretaceous, the early Maastrichtian around {{Ma|72}}.{{Cite journal|last1=Fischer|first1=V.|last2=Benson|first2=R. B. J.|last3=Druckenmiller|first3=P. S.|last4=Ketchum|first4=H. F.|last5=Bardet|first5=N.|date=March 2018|title=The evolutionary history of polycotylid plesiosaurians|url= |journal=Royal Society Open Science|language=en|volume=5|issue=3|pages=172177|doi=10.1098/rsos.172177|issn=2054-5703|pmc=5882735|pmid=29657811|bibcode=2018RSOS....572177F }} The possible latest surviving member Rarosaurus from the late Maastrichtian is more likely a crocodylomorph.{{Cite journal |last1=Alhalabi |first1=W. A. |last2=Bardet |first2=N. |last3=Sachs |first3=S. |last4=Kear |first4=B. P. |last5=Joude |first5=I. B. |last6=Yazbek |first6=M. K. |last7=Godoy |first7=P. L. |last8=Langer |first8=M. C. |year=2024 |title=Recovering lost time in Syria: New Late Cretaceous (Coniacian-Santonian) elasmosaurid remains from the Palmyrides mountain chain |journal=Cretaceous Research |volume=159 |at=105871 |doi=10.1016/j.cretres.2024.105871 |bibcode=2024CrRes.15905871A }}
With their short necks and large elongated heads, they resemble the pliosaurs, but closer phylogenetic studies indicate that they share many common features with the Leptocleididae and Elasmosauridae. They have been found worldwide, with specimens reported from New Zealand, Australia, Japan, Morocco, the US, Canada, Eastern Europe, and South America.{{Cite journal |author1=Druckenmiller, Patrick S. |author2=Russell, Anthony P. |name-list-style=amp |year=2009 |title=Earliest North American Occurrence Of Polycotylidae (Sauropterygia: Plesiosauria) From The Lower Cretaceous (Albian) Clearwater Formation, Alberta, Canada |url=http://www.bio.ucalgary.ca/contact/faculty/pdf/russell/335.pdf |journal=Journal of Paleontology |volume=83 |issue=6 |pages=361–392 |doi=10.1666/09-014.1 |bibcode=2009JPal...83..981D |s2cid=130695434 |url-status=dead |archive-url=https://web.archive.org/web/20110706211048/http://www.bio.ucalgary.ca/contact/faculty/pdf/russell/335.pdf |archive-date=2011-07-06 }}
Phylogeny
File:Trinacromerum_BW.jpg from the Late Cretaceous of Kansas]]
Cladogram after Albright, Gillette and Titus (2007).Albright III, L. B., Gillette, D. D., and Titus, A. L., 2007b. [http://www.plesiosaur.com/database/pdf/albrightetal_2007_part2.pdf Plesiosaurs from the Upper Cretaceous (Cenomanian-Turonian) Tropic Shale of southern Utah, part 2: polycotylidae] {{webarchive|url=https://web.archive.org/web/20110928220523/http://www.plesiosaur.com/database/pdf/albrightetal_2007_part2.pdf |date=2011-09-28 }}. Journal of Vertebrate Paleontology, v. 27, n. 1, p. 41-58.
{{clade| style=font-size:85%;line-height:85%
|label1=Plesiosauria
|1={{clade
|1=Plesiosaurus
|2=Tricleidus
|label3=Polycotylidae
|3={{clade
|1=Edgarosaurus
|2={{clade
|1=Thililua
|2={{clade
|label1=Palmulainae
|1={{clade
|1=UMUT MV 19965 (from Japan)
|2=Pahasapasaurus (=AMM 98.1.1)Schumacher, B. A., 2007, A new polycotylid plesiosaur (Reptilia; Sauropterygia) from the Greenhorn Limestone (Upper Cretaceous; lower upper Cenomanian), Black Hills, South Dakota: In: The Geology and Paleontology of the Late Cretaceous marine deposits of the Dakotas, edited by Martin, J. E., and Parris, D. C., The Geological Society of America, Special Paper 427, p. 133-146.
|3=Palmulasaurus }}
|label2=Polycotylinae
|2={{clade
|2={{clade
|2={{clade
|2=Polycotylus
}} }} }} }} }} }} }} }}
{{clade| style=font-size:85%;line-height:85%
|label1=Plesiosauroidea
|1={{clade
|label2=Leptocleidia
|2={{clade
|label2=Polycotylidae
|2={{clade
|2={{clade
|1=Edgarosaurus
|2={{clade
|1=QM F18041
|2={{clade
|2={{clade
|2={{clade
|1=Dolichorhynchops herschelensis
|2={{clade
|2=Manemergus
|3=Palmulasaurus }} }} }} }} }} }} }} }} }} }}
Below is a cladogram of polycotylid relationships from Ketchum & Benson, 2011.{{cite journal |author1=Hilary F. Ketchum |author2=Roger B. J. Benson |year=2011 |title=A new pliosaurid (Sauropterygia, Plesiosauria) from the Oxford Clay Formation (Middle Jurassic, Callovian) of England: evidence for a gracile, longirostrine grade of Early-Middle Jurassic pliosaurids |journal=Special Papers in Palaeontology |volume=86 |pages=109–129 }}
{{clade| style=font-size:85%;line-height:85%
|label1=Plesiosauroidea
|1={{clade
|label2=Leptocleidia
|2={{clade
|label2=Polycotylidae
|2={{clade
|1=Edgarosaurus
|2={{clade
|1={{clade
|2=QM F18041 }}
|2={{clade
|1={{clade
|2=Polycotylus
|3=Thililua }}
|2={{clade
|2={{clade
|1=Manemergus
|2={{clade
|1=Dolichorhynchops herschelensis
|2={{clade
|3=Palmulasaurus }} }} }} }} }} }} }} }} }} }}
References
{{Reflist}}
External links
- [https://web.archive.org/web/20080414142638/http://www.palaeos.com/Vertebrates/Units/220Lepidosauromorpha/220.820.html#Polycotylidae Palæos: The Vertebrates], Lepidosauromorpha: Cryptocleidoidea: Tricleidia
{{Portal|paleontology}}
{{Plesiosauria|Leptocleidia}}
{{Taxonbar|from=Q135400}}
Category:Sauropterygian families
Category:Cretaceous plesiosaurs
Category:Aptian first appearances
Category:Maastrichtian extinctions
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