The most primitive type of primate. Prosimians
are ancestral to all of today's monkeys and
apes, including humans. The group includes all
of the lemurs, tarsiers, and lorises.
| Captive mongoose lemurs, native to
Image credit: Primate Center, Duke University
Prosimians are typically, but not exclusively nocturnal, and have lower
brain-to-body mass ratios than other primates. Their habitat is restricted
to tropical woodlands.
Prosimians are characterized by:
- a well-developed sense of smell with
- only partial binocular vision
- claws on some digits
- immobilized upper lips
- a 2:1:3:3 dental formula, i.e., 2 incisors, 1 canine, 3 premolars,