Cockerellites Explained

Cockerellites is a genus of extinct temperate bass^[1] described from early Eocene-aged fossils found in the Green River Formation of Wyoming.^{[2] [3]} It is characterized by a sunfish-like body and its stout dorsal and anal spines. The type species, C. liops, was originally named as a species of Priscacara by Edward Drinker Cope upon creating the genus in 1877,^[4] but P. liops was moved to the newly created genus Cockerellites by D. Jordan and H. Hanibal in 1923.^[5] Some authors, such as Whitlock (2010), still consider Cockerellites liops as a species of Priscacara.

C. liops is based on the holotype USNM 4044, ^[6] and it was placed in Priscacara as P. liops but is now considered a separate genus.^[7] C. liops was originally seen as the most common species of Priscacara within the Green River lacustrine deposits, and at specific locations, it outnumbers P. serrata by over 3:1. The two species differ in the number of dorsal and anal fin rays, as well as possibly a coarser serrated rear edge of the preopercle in P. serrata. C. liops also has small conical teeth on the pharyngeal jaw, whereas P. serrata has large grinding tooth plates, suggesting a diet of snails and crustaceans.^[8]

Notes and References

1. Whitlock . J. A. . 2010 . Phylogenetic relationships of the Eocene percomorph fishes Priscacara and Mioplosus . Journal of Vertebrate Paleontology . 30 . 4 . 1037–1048 . 10.1080/02724634.2010.483534.
2. 4853363. Cockerellites. 2021-04-10.
3. Web site: Fossilworks: Cockerellites . 17 December 2021 . fossilworks.org . Fossilworks.
4. E. D. . Cope . Edward Drinker Cope . 1877 . A contribution to the knowledge of the ichthyological fauna of the Green River shales . Bulletin of the United States Geological and Geographical Survey . 3 . 4 . 807–819.
5. D. S. . Jordan . H. . Hanibal . 1923 . Fossil sharks and rays of the Pacific slope of North America . Bulletin of the Southern California Academy of Sciences . 22 . 27–63 .
6. Book: Cope . E. D. . 1884 . The Vertebrata of the Tertiary formations of the West . Report of the United States Geological Survey of the Territories . 3 . 1–1009 . 978-0405106729.
7. Book: The Lost World of Fossil Lake: Snapshots from Deep Time . Grande, L. . 14 June 2013 . University of Chicago Press; Illustrated edition . 978-0226922966 . 169.
8. Grande . L. . 1984 . Paleontology of the Green River Formation, with a review of the fish fauna. . Geological Survey of Wyoming Bulletin . 63 . 1–333 .