11.1 Fossil Primates & Bipedality

how far back does the fossil record extend

65 mya

what is the current geologic era called

cenozoic

what is the current geologic era epoch

holocene

in which epoch did the earliest proto-primates appear

paleocene

in which epoch did the adaptive radiation of prosimians occur

eocene

which epoch was the warmest and wettest

eocene

in which epoch did anthropoids have their adaptive radiation

oligocene

what became of anthropoids from their adaptive radiation

old & new monkeys

what became of prosimians from their adaptive radiation

true primitive primates (?)

in which epoch did hominoids essentially have their adaptive radiation

miocene

in which epoch did our ancestors have their adaptive radiation

pliocene

in which epoch did the “ice age” occur

pleistocene

it is during the ___ when the earliest proto-primates such as purgatorious appear

paleocene

which is the only well-represented paloecene primate family initial candidate yet represents another “proto-primate” due to being too primitive and derived to be considered a “true primate”

plesiadapis

what is a derived characteristic of plesiadapis that is too derived to have given rise to subsequent primates

really large gap between incisors & premolars

approximately when did Laurasia break up

45 mya

what is the “Heyday of Prosimians”

adaptive radiation of prosimians and rodents

T or F: North America had prosimians up until about 12 million years ago but went extinct

true

what exactly is the adaptive radiation of prosimians and rodents

when there is an explosion of different kinds of; literally hundreds

during the “Heyday of Prosimians,” which are the best known primate families

adapidium & omomyids

an example of adapidium

adapis

an example of omomyids

eosimians

emergence of early anthropoids (?)

the “Heyday of Prosimians”

of the eocene primates, which is “lemur-like”

adapis

what is thought to have given rise to modern lemurs

adapis

what qualities does the adapis possess

post-orbital bar & reduced sense of smell

what is one descriptor of the oligocene

when Europe & Africa connect

what is another descriptor of the oligocene

having cooler, drier environments

what is the final descriptor of the oligocene

when most of earlier eocene prosimians go extinct

what is the “adaptive radiation of anthropoids”

a division between OWM & NWM

what is hypothesized to have resulted from the adaptive radiation of anthropoids

division between OWM & apes

which epoch does the apidium (parapithecidae) come from

oligocene

which is an example of parapithecidae

apidium

approximately when did apidium exist

36 mya

T or F: apidium possessed the qualities of 2-1-3-3 dental formulae & unfused mandible

false (2-1-3-3 formulae & fused mandible)

ancestor to all anthropoids (i.e. monkeys, apes, & humans) (?)

apidium

the appearence of “apidium-like” primates

~33 mya

component of the rafting hypothesis

simultaneous appearance of rodents in South America similar to those from Fayum

genetic comparisons indicate a greater similarity of NWM to

OWM

divergence between 50 - 35 mya

NWM & OWM

example of propliopithecidae

propliopithecus

characteristics of propliopithecus

2-1-2-3 dental formulae, fused mandible, & highly sexually dimorphic

propliopithecus is possibly ancestral to ___

OWMs, apes, & humans

a species of propliopithecidae

aegyptopithecus

what does a mosaic of features mean

exhibiting both primitive & derived characteristics

T or F: aegyptopithecus exhibits a mosaic of features

true

specific qualities of aegyptopithecus

small brain & large snout

aegyptopithecus might be ancestral to all ___

OWM

what is a shared characteristic between all living apes & humans and aegyptopithecus

Y-5 molar pattern

primitive characteristics of aegyptopithecus

long snout, small brain, tail

derived(?) characteristics of aegyptopithecus

spatulate incisors, Y-5 molar pattern, & sinus patterns

T or F: the

the miocene

around when did Africa and Asia make contact with one another

~16 mya

what are the best known fossil groups

hominoids

what are proconsulids

African apes

what are dryopiths

European apes

what are ramapiths

Asian apes

example of a proconsulid

afropithecus

example of a dryopith

dryopithecus

example of a ramapith

sivapithecus

another example of a ramapith

gigantopithecus

T or F: proconsul is a very early fossil ape

true

T or F: proconsul is very large

false (not very large)

T or F: proconsul is fairly similar to modern living apes seen today

false (not much like)

T or F: proconsul exhibits characteristics/a combination of features not seen among modern apes

true

proconsul had this type of vertebrate & hipe

gibbon-like

proconsul had this type of hindlimb

ape-like

proconsul had this type of shoulder & elbow

ape-like

proconsul had this type of forearm & hands

OWM-like

what was very similar to modern day gorillas and may have given rise to them

afropithecus

example of a European Miocene ape

dryopith

example of an Asian Miocene ape

ramapith

type of ramapith

sivapithecus

Asian Miocene ape that is similar in skull/teeth to modern day organgutans, but the body not similar at all

sivapithecus

very largest of all Miocene apes

gigantopithecus

in terms of genetic divergences, the suggestion is that humans would have shared a common ancestry with which particular of the great apes

chimps & bonobos

in the middle Miocene, foraging occurred mainly…

within large food resources

in the end Miocene, foraging occurred mainly…

among small food patches

what is the primary characteristic that makes Hominids distinct

bipedality

bipedality

habitual, obligate upright locomotion using the hind limbs using a striding gait

three characteristics that we can use to detect bipedality in the fossil record

location of the foramen magnum, looking at the spinal column, and the pelvis

in humans, the foramen magnum is…

closer to the center of the skull / directly under / through the base

in apes, the foramen magnum is…

further toward the back of the skull

shape of spinal column in apes

C-shaped

shape of spinal column in humans

S-shaped

what is the structure of the spinal column in order to bear additional weight associated with upright locomotion

it widens

what is the unique feature of the human spinal column that is not seen in non-human primates

the vertebral column gets progressively wider

characteristics of the human pelvis

wide, short, & cupped

characteristics of the pelvis of apes

long & flat

what does valgus refer to

the angle of the femur

characteristics of the femur in NHP

straight toward tibia

characteristics of the femur in humans

angled outward & toward tibia

why does the valgus exist

it brings the center of gravity underneath the body as striding occurs

T or F: valgus develops for functional reasons (i.e. paraplegics do not develop)

true

characteristics of limbs in terms of proportions for NHP

upper are longer than the lower

characteristics of limbs in terms of proportions for humans

lower are 1.5x longer than the upper

characteristics of the feet for NHP

big toe is off to the side and has a prehensile foot (saddle joint)

characteristics of the feet for humans

big toe is in line with the other toes and is arched

what is the important fossil site for footprints

Laetoli

in which environment did bipedalism get selected for

terminal miocene / early pliocene