Cockerellites

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.^[1]

Cockerellites Temporal range: Early Eocene, ~53.5–48.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Specimen of C. liops from the 18 inch layer of the Green River Formation, Wyoming
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Moroniformes
Family:	Moronidae
Genus:	†Cockerellites Jordan & Hanibal, 1923
Type species
†Cockerellites liops (Cope, 1877)
Synonyms
Priscacara liops Cope, 1877

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]

References

1. Whitlock, J. A. (2010). "Phylogenetic relationships of the Eocene percomorph fishes †Priscacara and †Mioplosus". Journal of Vertebrate Paleontology. 30 (4): 1037–1048. doi:10.1080/02724634.2010.483534.
2. "Cockerellites". Global Biodiversity Information Facility. Retrieved 2021-04-10.
3. "Fossilworks: Cockerellites". fossilworks.org. Fossilworks. Retrieved 17 December 2021.
4. Cope, E. D. (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. Jordan, D. S.; Hanibal, H. (1923). "Fossil sharks and rays of the Pacific slope of North America". Bulletin of the Southern California Academy of Sciences. 22: 27–63.
6. Cope, E. D. (1884). The Vertebrata of the Tertiary formations of the West. Report of the United States Geological Survey of the Territories. Vol. 3. pp. 1–1009. ISBN 978-0405106729.
7. Grande, L. (14 June 2013). The Lost World of Fossil Lake: Snapshots from Deep Time. University of Chicago Press; Illustrated edition. p. 169. ISBN 978-0226922966.
8. Grande, L. (1984). "Paleontology of the Green River Formation, with a review of the fish fauna" (PDF). Geological Survey of Wyoming Bulletin. 63: 1–333.