3 Human Fossils (Lab)

Question 1

what fossil evidence is in the Pliocene

Answer 1

hominin genus Australopithecus,

Question 2

hallmark of hominin evolution

Answer 2

bipedal locomotion

Question 3

early hominins were less human-like in the____ than in the _____

Answer 3

cranium

post-crania

Question 4

all show

anatomical evidence of (2)

Answer 4

(1) habitual bipedalism and (2) reduction of canine size

Question 5

Sahelanthropus tchadensis (3)

Answer 5

earliest
bipedal ( foramen magnum is placed anteriorly )
apical wear on the canine teeth

Question 6

Orrorin tugenensis (1)

Answer 6

proximal femur, provides convincing evidence for bipedal

Question 7

Ardipithecus (3)

Answer 7

canines larger than Australopithecus, but smaller than those of most great apes

anatomy of the pelvis and forward placement of the foramen magnum indicate bipedal

well adapted for climbing and arboreal suspension

Question 8

Australopithecus anamensis (2)

Answer 8

thick enamel

moderate canines

Question 9

Australopithecus afarensis (3)

Answer 9

morphology of the hind limb shows adaptations for bipedalism

sexually dimorphic

canines are reduced

Question 10

Paranthropus robustus (3)

Answer 10

large cheek teeth,
very thick dental enamel,
and very large chewing muscle attachment sites

Question 11

Paranthropus boisei (4)

Answer 11

large bite forces
sagittal crest
“megadont” (huge) molars
sexually dimorphic,

Question 12

_______ varies among the
australopithecines

some show -

Answer 12

dental morphology

exhibit megadontia

Question 13

early hominins had different______ than
modern humans

shown by 2 (but 3 things show #2)

Answer 13

diets

Tooth size and morphology
size and strength of the two major chewing muscles (some degree of lateral flare, sagittal crests, dish shaped face)

Question 14

Humans have a greater number of ______

Answer 14

lumbar vertebrae

Question 15

In humans, the_____ joint surface is_____

human _____ is considerably____ superio-inferiorly (top to bottom) and_____

Answer 15

sacroiliac
wide

os coxa
shorter
broader

Question 16

humans have a_____-facing ilium

the lesser _______ to prevent the ______when the body is supported on a single leg

Answer 16

laterally

gluteal muscles
collapse of the hip joint

Question 17

having the ______ close to the center of gravity

gives australopithecines greater mechanical advantage in _______ by decreasing the _______ arm relative to the______ arm

Answer 17

hip sockets
abducting the pelvis
length of the load
length of the force

Question 18

modern human pelvis seems to be structured as a compromise between two functional needs (2)

Answer 18

efficient bipedalism and

allowing large-brained infants to pass through the birth canal

Question 19

shaft of the femur is_____ = ______

allows a biped to place its

Answer 19

angled; “valgus knee”.

feet directly below its center of gravity

Question 20

Our feet are unique among hominoids in having an ________ that is _______

first metatarsal in bipeds is

Answer 20

adducted big toe (hallux)
parallel with the other toes

relatively larger

Question 21

the shape of the medial cuneiform:
is _____ and not adapted for rotary movement. This __________ and permits
independent movement of the great toe

Answer 21

flat in bipeds

surface is rounded in apes