ANT - L05 [Oct 14 2010]

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15 Feb 2011
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L05 ± Oct 14
Paleocene (55.8 to 65.5 millions of years ago [MYA])
x The climate was much hotter and more humid (about 3x current)
x Scientists think this is when primates first showed up
x Paleocene & Primate-Like Mammals: Plesiadapiformes
o Body Size ± tiny, shrew-sized to size of small dog
o Niche ± likely solitary, nocturnal quadrupeds; well-developed sense of
smell
o Diet ± insects and seeds
o Used to be classified as primates because of primate-like teeth and limbs
that are adapted for arboreal lifestyle
x Plesiadapids were not considered primates for a long time based on looks
(phylogenetic). Why?
o No postorbital bar
o Claws instead of nails
o Eyes placed on side of head
o Enlarged incisors
x The more modern approach suggests that Plesiadapids are primates
o Primitive characters (patterns from current species) are ignored
o Derived characters (patterns from common ancestors) are the ones that
matter
Eocene (33.9 MYA)
x Climate is cooler than that of Paleocene but still hotter than current climate (2x)
o Consistent pattern of lowering temperatures throughout the Eocene
x There were two main Eocene primate families:
x Adapidae
o Body Size ± 100g to 6900g
o Diurnal and nocturnal forms
o Mainly arboreal quadrupeds, some may have been specialized leapers
o Smaller adapids ate mostly fruit and insects, larger forms ate more fruit as
well as leaves
No current organism can break down and take energy from leaves
o Possibly led to lemurs
x Omomyidae
o Body Size ± 45g to 2500g
o Some nocturnal; others diurnal
o Omomyids thought to been specialized leapers
o Teeth ± adapted for eating insects and soft fruits, only few species were
leaf-eaters
o Possibly led to tarsiers
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Oligocene
x Oligocene primates:
www.notesolution.com
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