Archicebus

Archicebus achilles Temporal range: Early Eocene PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorhini
Family:	Archicebidae Ni et al. 2013
Genus:	Archicebus Ni et al. 2013
Species:	A. achilles Ni et al. 2013
Type species
Archicebus achilles Ni et al. 2013

Archicebus is a genus of fossil primates that lived in the early Eocene forests (~55 million years ago) of what is now Jingzhou in the Hubei Province in central China, discovered in 2003. The only known species, A. achilles, was a small primate, estimated to weigh approximately 20–30 grams (0.71–1.06 oz), and is the only known member of the family Archicebidae. As of 2013, it is the oldest fossil haplorhine primate skeleton discovered, and is most closely related to tarsiers and the fossil omomyids, although A. achilles is suggested to have been diurnal whereas tarsiers are nocturnal. Resembling tarsiers and simians (monkeys, apes, and humans), it was a haplorhine primate, and it also may have resembled the last common ancestor of all haplorhines as well as the last common ancestor of all primates. Its discovery further supports the hypothesis that primates originated in Asia, not in Africa.

Archicebus achilles was named for being the oldest known primate skeleton (as of 2013^[update]) and for its distinguishing calcaneus (heel bone). The generic name, Archicebus, was constructed from arche (ἀρχή), the Ancient Greek word for "beginning", and cebus, the Latin version of the Ancient Greek kêbos (κῆβος), which refers to a long-tailed monkey. The species name, achilles, is a reference to Achilles, the Greek hero of the Trojan War from Greek mythology.