Hemiacodon

Hemiacodon Temporal range: 46.2–42.0  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Upper jaw of H.gracilis
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorhini
Family:	† Omomyidae
Genus:	† Hemiacodon Marsh, 1872
Species
H. gracilis (Marsh, 1872) H. engardae (Murphey & Dunn, 2009) H. casamissus (Beard et al. 1992) H. pygmaeus (Wortman, 1904)

Hemiacodon is a genus of early Eocene omomyid from North America. ^[1]

Description

Hemiacodon is known from mainly dentary material, and the various species are differentiated by the shape and development of shearing crests on the molar. This variation in molar shape indicates the different species had varied diets. ^[2]

Paleoecology

Hemiacodon lived alongside many other primates in western North America, including Pelycodus , Notharctus and Macrotarsius . ^[2] Older literature speculates that the diversity of primates in early Eocene California was caused by them being temporary "havens", meaning the environment was more accommodating than surrounding areas. ^[3]

References

1. "Mindat.org". www.mindat.org. Retrieved 2025-09-17.
2. Murphey, Paul C.; Dunn, Rachel H. (August 2009). "Hemiacodon engardae, a new species of omomyid primate from the earliest Uintan Turtle Bluff Member of the Bridger Formation, southwestern Wyoming, USA". Journal of Human Evolution. 57 (2): 123–130. Bibcode:2009JHumE..57..123M. doi:10.1016/j.jhevol.2009.05.006. ISSN   1095-8606. PMID   19625072.
3. Lillegraven, Jason A. (1980). "Primates from Later Eocene Rocks of Southern California". Journal of Mammalogy. 61 (2): 181–204. doi:10.2307/1380040. ISSN   0022-2372. JSTOR   1380040.