Eothyris is a genus of extinct synapsids in the family Eothyrididae from the Permian. It was an insectivorous animal, closely related to Oedaleops. Only the skull of Eothyris, first described in 1937, is known. It had a 6-centimetre-long (2.4-inch) skull, and its total estimated length is 30 centimetres (12 inches).
| Eothyris Temporal range: Early Permian,[1]
| |
|---|---|
| |
| Holotype skull | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | †Caseasauria |
| Family: | †Eothyrididae |
| Genus: | †Eothyris Romer, 1937 |
| Type species | |
| Eothyris parkeyi Romer, 1937
| |
Discovery
Eothyris parkeyi was one of many new species of "pelycosaurs" discovered by Alfred Sherwood Romer as part of a series of paleontological expeditions for the Museum of Comparitive Zoology (MCZ). The genoholotype (type specimen of a genus) and only known specimen of Eothyris is a complete skull and associated jaws, with the collection number MCZ 1161. This skull was collected in Early Permian sediments of the Petrolia or Belle Plains Formation (part of the Wichita Group) near Dundee, Texas.[2] The generic name is Greek for "dawn opening", likely in reference for its status as one of the most primitive known synapsids. The specific name refers to J.R. Parkey, a local landowner who assisted the MCZ field crew in collecting fossils on his property. Eothyris was briefly described by Romer in 1937, and given a more comprehensive description by Romer and Llewellyn Ivor Price in 1940.[3]
Description
Eothyris is only known from its skull, which is short and broad. With a total skull length of 5.7 cm (2.25 in), Benson et al. estimated the body to be 30 cm (12 in) long. The major distinguishing features of the skull are that it possessed a pair of long, large, fang-like teeth on each side of the upper jaw. The use for these teeth is not known, but Eothyris might have used them to eat small prey. All teeth in its mouth were sharp and pointed, with all but the enlarged four fangs being small and short. The skull is short and broad, two features which suggest that Eothyris had a snapping, rapid bite.[1]
Classification
Eothyris is classified in the monophyletic family Eothyrididae. It is one of two genera in the family, the other being Oedaleops. The family is grouped in Caseasauria, and only cranial remains are known from it. The family is greatly supported, with nine dental and cranial features. Below is the cladogram of the analysis of Riez et al. (2009).[4]
References
Footnotes
- ^ a b Benson et al. 2012, p. 191.
- ^ Romer, Alfred Sherwood (1937). "New Genera And Species Of Pelycosaurian Reptiles" (PDF). Proceedings of the New England Zoölogical Club. 16: 89–97. Archived from the original (PDF) on 2 December 2018.
- ^ Romer, A.S.; Price, L.I. (1940). "Review of the Pelycosauria". Geological Society of America Special Paper. 28: 1–538. doi:10.1130/spe28-p1.
- ^ Riez et al. 2009.
Citations
- Benson, R.; Brusatte, S.; Hone, D.; Naish, D.; Xu, X.; Anderson, J.; Clack, J.; Duffin, C.; Milner, A.; Parsons, K.; Prothero, D.; Johanson, Z.; Dennis-Bryan, K. (2012) [2009]. Ambrose, Jamie; Gilpin, David; Hirani, Salima; Jackson, Tom; Joyce, Nathan; Maiklem, Lara; Marriott, Emma; Nottage, Claire; van Zyl, Meizan (eds.). Prehistoric Life: A Definitive Visual History of Life on Earth. Dorling Kindersley. pp. 1–512. ISBN 978-0-7566-9910-9. OCLC 444710202.
- Reisz, R. R.; Godfrey, S. J.; Scott, D. (2009). "Eothyris and Oedaleops: Do these Early Permian synapsids from Texas and New Mexico form a clade?". Journal of Vertebrate Paleontology. 29: 39. doi:10.1671/039.029.0112.
External links
 | This Synapsida-related article is a stub. You can help Wikipedia by expanding it. |