Polycotylidae is a family ofplesiosaurs from theCretaceous, a sister group toLeptocleididae. They are known as false pliosaurs. Polycotylids first appeared during theAlbian 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 earlyMaastrichtian around72 million years ago.[3] The possible latest surviving memberRarosaurus from the late Maastrichtian is more likely acrocodylomorph.[4]
^Alhalabi, W. A.; Bardet, N.; Sachs, S.; Kear, B. P.; Joude, I. B.; Yazbek, M. K.; Godoy, P. L.; Langer, M. C. (2024). "Recovering lost time in Syria: New Late Cretaceous (Coniacian-Santonian) elasmosaurid remains from the Palmyrides mountain chain".Cretaceous Research.159. 105871.Bibcode:2024CrRes.15905871A.doi:10.1016/j.cretres.2024.105871.
^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.
^Ketchum, H. F. & Benson, R. B. J. (2010). "Global interrelationships of Plesiosauria (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses".Biological Reviews.85 (2):361–392.doi:10.1111/j.1469-185X.2009.00107.x.PMID20002391.S2CID12193439.
^Hilary F. Ketchum; Roger B. J. Benson (2011). "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".Special Papers in Palaeontology.86:109–129.
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