Ectocion

Ectocion
Temporal range: Paleocene - Eocene
Ectocion osbornianus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Eutheria
Superorder: Laurasiatheria?
Order: Condylarthra
Family: Phenacodontidae
Genus: Ectocion
Cope, 1882
Species

E. cedrus (Thewissen, 1990)
E. collinus (Russell, 1929)
E. ignotum (Novacek et al., 1991)
E. major (Patteron & West, 1973)
E. mediotuber (Thewissen, 1990)
E. osbornianus (Cope, 1882)
E. parvus (Granger, 1915)
E. superstes (Granger, 1915)

Ectocion (sometimes Ectocyon) is an extinct genus of placental mammals of the order Condylartha. The genus was earlier classified as Gidleyina (Simpson 1935) and Prosthecion (Patterson and West 1973)[1]

Paleocene specimens of these hoofed, ground-dwelling herbivores have been found in Canada (Alberta, Saskatchewan) and the United States (Colorado, Montana, North Dakota, and Wyoming). Eocene specimens have been found in Mexico and the United States (Colorado, Mississippi, Wyoming). [1]

One of the dramatic effects of the Paleocene–Eocene Thermal Maximum (PETM) was some animals evolving smaller bodies. Fossilized Ectocion jaw bones show that this genus was smaller during (E. parvus, 55.5 mya) the PETM than its relatives before (E. osbornianus, 55.6 mya) and after (E. osbornianus, 55.3 mya) the brief climatic peak period. [2]

References

  1. ^ a b "Ectocion". The Paleobiogy Database. http://www.paleodb.org/cgi-bin/bridge.pl?action=basicTaxonInfo&taxon_no=42261. Retrieved January 2010. 
  2. ^ Gingerich, Phil. "Big Little Big". Smithsonian National Museum of Natural History. http://forces.si.edu/atmosphere/03_00_05.html. Retrieved January 2010.