Euclastes is an extinct genus of sea turtles that survived the Cretaceous–Paleogene mass extinction. The genus was first named by Edward Drinker Cope in 1867, and contains three species. E. hutchisoni, was named in 2003 but has since been reassigned to the genus Pacifichelys,[3] while E. coahuilaensis named in 2009 was reassigned as Mexichelys coahuilaensis in 2010.[4][5]
| Euclastes | |
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| Euclastes sp. skeleton | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Clade: | Pancheloniidae |
| Genus: | †Euclastes Cope, 1867 |
| Species[1] | |
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| Synonyms | |
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Description
edit
Unlike the sea turtles Toxochelys and Eochelone, Euclastes has a secondary palate. However, the secondary palate of Euclastes is not as extensive as it is in Ctenochelys and Angolachelys.[6] The genus can be distinguished by later sea turtles based on its broad, low skull; broad, flat palate; wide, flat dentary bone with an elongated symphysis; and low tomial ridge on the beak. The widened palate and dentaries give Eochelone wide, flat jaws suitable for crushing hard-shelled organisms.[3]
Classification
editSpecies
edit- †E. acutirostris Jalil et al., 2009
- †E. platyops Cope, 1867
- †E. wielandi (Hay, 1908)
Phylogeny
editCladogram based on Lynch and Parham (2003)[3] and Parham and Pyenson (2010):[7]
| Cheloniidae sensu lato |
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Distribution
editFossils of Euclastes have been found in:[8]
- Maastrichtian
- Bentiaba, Angola[9]
- Quiriquina Formation, Chile
- Hornerstown and Navesink Formations, New Jersey
- Paleocene
- Jagüel and Roca Formations, Argentina
- Aquia and Brightseat Formations, Maryland
- Sidi Chennane and Couche 2 Formation, Morocco
- Eocene
- Parkers Ferry Formation, South Carolina
References
edit- ^ Parham, James F.; Pyenson, Nicholas D. (March 2010). "New sea turtle from the Miocene of Peru and the iterative evolution of feeding ecomorphologies since the Cretaceous". Journal of Paleontology. 84 (2): 231–247. Bibcode:2010JPal...84..231P. doi:10.1666/09-077R.1. ISSN 0022-3360. S2CID 62811400.
- ^ Ullmann, S. G.; Carr, E. (2021). "Catapleura Cope, 1870 is Euclastes Cope, 1867 (Testudines: Pan-Cheloniidae): synonymy revealed by a new specimen from New Jersey". Journal of Systematic Palaeontology. 19 (7): 491–517. Bibcode:2021JSPal..19..491U. doi:10.1080/14772019.2021.1928306. S2CID 236504236.
- ^ a b c Lynch, S.C.; Parham, J.F. (2003). "The first report of hard-shelled sea turtles (Cheloniidae sensu lato) from the Miocene of California, including a new species (Euclastes hutchisoni) with unusually plesiomorphic characters" (PDF). PaleoBios. 23 (3): 21–35.[permanent dead link]
- ^ Euclastes coahuilaensis from the Paleobiology Database
- ^ Exibidos fósseis de tartarugas com 72 mi de anos
- ^ Mateus, Octávio; Jacobs, Louis; Polcyn, Michael; Schulp, Anne S.; Vineyard, Diana; Buta Neto, André; Telles Antunes, Miguel (December 2009). "The Oldest African Eucryptodiran Turtle from the Cretaceous of Angola". Acta Palaeontologica Polonica. 54 (4): 581–588. doi:10.4202/app.2008.0063.
- ^ James F. Parham; Nicholas D. Pyenson (2010). "New Sea Turtle from the Miocene of Peru and the Iterative Evolution of Feeding Ecomorphologies since the Cretaceous". Journal of Paleontology. 84 (2): 231–247. Bibcode:2010JPal...84..231P. doi:10.1666/09-077R.1. S2CID 62811400.
- ^ Euclastes at Fossilworks.org
- ^ Mateus, O., M. J. Polcyn, L. L. Jacobs, R. Arujo, A. S. Schulp, J. Marinheiro, B. Pereira and D. Vineyard. 2012. Cretaceous amniotes from Angola: dinosaurs, pterosaurs, mosasaurs, plesiosaurs, turtles. Actas de V Jornadas Internacionales sobre Paleontologia de Dinosaurios y su Entorno, Salas de los Infantes, Burgos 71-105