Family
Valid Extinct

Polycotylidae

Williston 1908

Polycotylidae is a family of plesiosaurs from the Cretaceous. 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 Maastrichtian around 66 million years ago. The possible latest surviving member Rarosaurus from the late Maastrichtian is more likely a crocodylomorph.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
102
Group
Sauroptérygiens
Carnivore aquatic, depth=surface Marine
Polycotylidae
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Wikimedia
PBDB Wikipedia
Classification
Sauropterygia Suborder
Plesiosauria Order
Plesiosauroidea Superfamily
Polycotylidae Family
Fossil sites 100 geolocated sites
Distribution
Top countries
🇺🇸 United States
46
🇨🇦 Canada
12
🇷🇺 Russia
11
🇳🇿 New Zealand
8
🇦🇷 Argentina
7
🇸🇪 Sweden
3
🇦🇺 Australia
2
🇵🇱 Poland
2
🇲🇽 Mexico
2
🇲🇦 Morocco
2
Geological formations
Greenhorn Limestone
6
Conway
6
Tropic Shale
5
Carlile Shale
5
La Colonia
4
Agua Nueva
2
Akrabou
2
Santa Marta
2
Temporal distribution
Maastrichtian (72.2–66 Ma)
12
Campanian (83.6–72.2 Ma)
32
Santonian (85.7–83.6 Ma)
9
Coniacian (89.8–85.7 Ma)
7
Turonian (93.9–89.8 Ma)
22
Cenomanian (100.5–93.9 Ma)
12
Albian (113.2–100.5 Ma)
3
Aptian (121.4–113.2 Ma)
2
Kimmeridgian (154.8–149.2 Ma)
1
Synonyms (4)
Cimoliasaurus leucoscopelus nomen dubium, species not entered Polycotylidae
Dolichorhynchopidae subjective synonym of Polycotylidae
Polycotylus brevispondylus nomen vanum, species not entered Polycotylidae
Polycotylus ichthyospondylus tanais nomen vanum, species not entered Polycotylidae
Images 2
Bibliography
Original description
F. R. O'Keefe. 2001. A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia: Sauropterygia). Acta Zoologica Fennica 213:1-63
Bibliography (65)
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