December 3 Primates 12/12/2012 8:47:00 AM
How and Where Did Primates Originate?
o Primates became primates by adapting to life in trees
o Enhanced sight (depth perception)
o Grasping hands and feet
Visual predation hypothesis
o Binocular vision, grasping hands and feet, and reduced claws
developed because they facilitated the capture of insects.
o First adapted to life in the bushy forest undergrowth and low
The earliest primates date to at least the Paleocene (65-54 million
years ago), but possibly appeared as early as Late Cretaceous.
The Eocene (54-38 million years ago) was the epoch of
__________ with at least 60 different genera in two families.
The Big Split
Anthropoid line split from Prosimian line
o by Paleocene or Eocene
o (“Higher Primates”)
o spider monkeys
o (“Lower Primates” )
Major differences between Prosimians and Anthropoids
Anthropoid eyes are rotated more forward compared to prosimians.
Anthropoids have a fully enclosed bony eye socket.
Anthropoids have a dry nose separate from the upper lip.
Anthropoid molars more complex and differentiated than prosimian Early Anthropoids
Parapithecines (e.g. Aegytopithecus)
After splits, anthropoids came into their own, transitional
By the Oligocene (38-23 million years ago), anthropoids dominated
over lemurs and relatives.
The beginnings of the anthropoid group are traced to generalized
forms such as the parapithecines (e.g., Aegyptopithecus).
Body of Aegyptopithecus resembled that of a lemur, but teeth more
Aegyptopithecus or related form is though to be the common
relative of the New World Monkeys and the Old World Monkey-
Dryopithecines (e.g. Proconsul
Dryopithecines (e.g. Proconsul) thought to be the common ancestor
of the Old World Monkeys and Ape-Human Line
Proconsul’s teeth have similarities with modern apes, but below the
neck the skeleton is more monkey-like.
Living Representatives (Anthropoids)
Old World Monkeys
o (baboons, macaques, mandrills)
Old world distinguished fro