A new genus and species of medium-sized fossil primate, Myanmarpithecus yar
shensis, is described from the lastest middle Eocene sediments of Pondaung,
central Myanmar (Burma). The specimens consist of right maxillary fragment
s with P-4-M-3 and a left mandibular corpus with C-P-3 and M2-3. To date, t
hree purported anthropoids have been discovered from the Pondaung Formation
: Pondaungia and Amphipithecus (Amphipithecidae) and Bahinia (Eosimiidae),
Myanmarpithecus differs from these other Pondaung primates in having cingul
ar hypocones on upper molars and in lacking paraconids on M2-3. Although My
anmarpithecus resembles some utahiin omomyines in superficial aspects of th
e morphology of M2-3 (i.e., mesiodistally compressed molar trigonid and ena
mel crenulation), the morphological analysis of upper molars and lower prem
olars indicates that it is neither an omomyoid nor an adapoid but is more d
erived than fossil prosimians (such as adapoids, omomyoids, and tarsiers) a
nd more anthropoid-like. On the other hand, it is more primitive (prosimian
-like) than early anthropoids from the late Eocene/early Oligocene of the F
ayum, Egypt. Myanmarpithecus is likely to be an tarry, primitive anthropoid
("protoanthropoid"). (C) 2001 Academic Press.