Genus
Valid Extinct

Polycotylus

Cope 1869

Polycotylus is a genus of plesiosaur within the family Polycotylidae. The type species is P. latippinis and was named by American paleontologist Edward Drinker Cope in 1869. Eleven other species have been identified. The name means 'much-cupped vertebrae', referring to the shape of the vertebrae. It lived in the Western Interior Seaway of North America toward the end of the Cretaceous. One fossil preserves an adult with a single large fetus inside of it, indicating that Polycotylus gave live birth, an unusual adaptation among reptiles.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
10
Group
Sauroptérygiens
Carnivore aquatic, depth=surface Marine
Polycotylus
click to enlarge
Polycotylus latipinnis specimen (LACM 129639) containing a fetus on display at the Natural History Museum of Los Angeles County. © Jonathan Chen · CC BY-SA 4.0 · Wikimedia
PBDB ↗ Wikipedia ↗
Classification
Sauropterygia Suborder
›
Plesiosauria Order
›
Plesiosauroidea Superfamily
›
Polycotylidae Family
›
Polycotylinae Subfamily
›
Polycotylus Genus
Fossil sites 10 geolocated sites
Distribution
Top countries
🇺🇸 United States
8
🇫🇷 France
1
🇷🇺 Russia
1
Geological formations
Niobrara
5
Argiles de Châtillon
1
Frontier
1
Mooreville Chalk
1
Pierre Shale
1
Temporal distribution
Campanian (83.6–72.2 Ma)
3
Santonian (85.7–83.6 Ma)
3
Coniacian (89.8–85.7 Ma)
2
Cenomanian (100.5–93.9 Ma)
1
Kimmeridgian (154.8–149.2 Ma)
1
Species (4)
Polycotylus dolichopus subjective synonym of Polycotylus latipinnis 90 Ma
Polycotylus latipinnis 90 Ma
Polycotylus sopozkoi 84 Ma
Polycotylus suprajurensis 152 Ma
Images 1
Bibliography
Original description
E. D. Cope. 1869. Synopsis of the Extinct Batrachia, Reptilia and Aves of North America. Part I. Transactions of the American Philosophical Society, New Series 14:1-104 DOI ↗
Bibliography (10)
V. M. Efimov, I. A. Meleshin, and A. V. Nikiforov. 2016. A New Species of the Plesiosaur Genus Polycotylus from the Upper Cretaceous of the Southern Urals. Paleontological Journal 50(5):494-503 DOI ↗
B. A. Schumacher and J. E. Martin. 2016. Polycotylus latipinnis Cope (Plesiosauria, Polycotylidae), a nearly complete skeleton from the Niobrara Formation (Early Campanian) of southwestern South Dakota. Journal of Vertebrate Paleontology 36(1):e1031341:1-15 DOI ↗
F. R. O'Keefe and L. M. Chiappe. 2011. Viviparity and K-selected life history in a Mesozoic marine Plesiosaur (Reptilia, Sauropterygia. Science 333(870):870-873 DOI ↗
F. R. O'Keefe. 2004. On the cranial anatomy of the polycotylid plesiosaurs, including new material of Polycotylus latipinnis, Cope, from Alabama. Journal of Vertebrate Paleontology 24(2):326-340 DOI ↗
G. W. Storrs. 1999. An examination of Plesiosauria (Diapsida: Sauropterygia) from the Niobrara Chalk (Upper Cretaceous) of Central North America. Paleontological Contributions of the University of Kansas 11:1-15
S. W. Williston. 1906. North American plesiosaurs: Elasmosaurus, Cimoliasaurus, and Polycotylus. The American Journal of Science, series 4 21:221-236 DOI ↗
S. W. Williston. 1905. A new armored dinosaur from the Upper Cretaceous of Wyoming. Science 22(564):503 DOI ↗
S. W. Williston. 1903. North American plesiosaurs, part 1. Geological Series Field Museum of Natural History 3(1):1-77 DOI ↗
H.-E. Sauvage. 1876. Notes sur les reptiles fossiles [Notes on fossil reptiles]. Bulletin de la Société Géologique de France, 3e série 4:435-444
E. D. Cope. 1869. Synopsis of the Extinct Batrachia, Reptilia and Aves of North America. Part I. Transactions of the American Philosophical Society, New Series 14:1-104 DOI ↗