Cenozoic Era

Tertiary Period Epochs

Paleocene : (65-55 mya)
Eocene : (55-34 mya)
Oligocene : (34-24/23 mya)
Miocene : (24/23-5 mya)
Pliocene : (5 mya-1.8)

35 - 23.5 mya

26 mya : earliest African apes, first hominoids

first definite higher primate species

global cooling, diverse habitats, reduced rainforest

age of apes

after 17 mya: cooling and drying period, fewer trees, open expanses

11-5 mya: fossil record gap (possible sahelanthropus, Orrorin, Ardipithecus ramidus)

4.5 mya: fossil evidence first bipeds

5.2-1.6 mya: various bipedals + migrations out of Africa

Mesozoic/Cenozoic boundary

meteor impact = mass extinction + cooling

adaptive radiation of mammals

(possible speciation)

N. America

may link eurprimates and proprimates

opposable, grasping

natural selection for arboreal traits

clavicles, nails, grasping hands and feet

=

stability, good grasping & manipulation

flowering plants (angiosperms) were unexploited in Cretaceous

grasping hands evolved for eating fruit

55 -34 mya

55 mya:

first primate characteristics, global warming, warm and wet

euprimates: adapids and omomyids

fossil prosimians

omomyids : nocturnal, may have led to tarsiers

adapids: diurnal, may have led to moden lumers, maybe anthropoids

Eosimias (42 mya, Eocene):

tarsals, esp. short calaneous possibly first true anthropoid

Biretia (37 mya, late Eocene):

two cusped (bicuspid) molars

Parapithecids (likely led to Old World Monkeys)

Propliopithecids (likely led to New World Monkeys)

Good suggestion/Likely:

Landbridge/islandhopping Africa to S.America

Not so much:

Independent origins/evolved in both continents

or

North American evolution

32-29 mya

mid-sagittal crest

arboreal quadruped

frugivores

arboreal: equally long arms and legs

quadrupeds

European

slower period of growth

fruit eater

longer arms than legs (close to modern apes)

Sivapithecus: 12-8 mya (India and Pakistan)

orgininally thought to be ancestor

Khoratpithecus: 9-6 mya (Thailand)

more likely or more direct ancestor

8 - 0.5 mya

bamboo, nuts and seeds

very large, likely quadruped similar to gorilla

Eocene

and

Miocene

limited mobility in shoulder joint

equal length arms and legs

limited elbow extension

deep ribcage

small hands

high degree of elbow extension

shallow ribcage

mobile shoulder

arms longer than legs

large hands

european

large body

tiny brain

specialized molars

65-55 mya

early primate-like mammals proprimates

lack: postorbital bar, convergent orbits, thumb