"Crocodylus" affinis is an extinct species of crocodyloid from the Eocene of Wyoming. Fossils were first described from the Bridger Formation by American paleontologist Othniel Charles Marsh in 1871. Marsh described the species, along with every other species of crocodyloid in the Bridger Formation, under the genus Crocodylus.[2] The known specimen of "Crocodylus" affinis is a skull found at Grizzly Buttes, Wyoming, measuring 13 inches in length on the upper surface.[3] Recent phylogenetic studies of crocodyloids show that "C." affinis is not a species of Crocodylus, but a genus has not yet been erected to include the species. Other Bridger species such as Crocodylus clavis and Brachyuranochampsa zangerli have been synonymized with "C." affinis.[4][5]
The below cladogram shows the results of the latest studies, which placed "C." affinis outside of Crocodyloidea, as more basal than Longirostres (the combined group of crocodiles and gavialids).[6]
^Marsh, O. C. (1871). Notice of some new fossil reptiles from the Cretaceous and Tertiary formations. American Journal of Science, s3-1(6), 447–459. doi:10.2475/ajs.s3-1.6.447
^de Buffrenil, V.; Buffetaut, E. (1981). "Skeletal growth lines in an Eocene crocodilian skull from Wyoming as an indicator of ontogenic age and paleoclimatic conditions". Journal of Vertebrate Paleontology. 1 (1): 57–65. doi:10.1080/02724634.1981.10011879.
^Brochu, C. A. (2000). "Phylogenetic relationships and divergence timing of Crocodylus based on morphology and the fossil record". Copeia. 2000 (3): 657–673. doi:10.1643/0045-8511(2000)000[0657:pradto]2.0.co;2.
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