Australopiths

Question 1

Australopiths - two types

Answer 1

gracile = Australopithecus
robust = Paranthropus

Question 2

major trends in Australopiths

Answer 2

• dentition: reduced size, larger cheek teeth, thicker enamel
  –> Paranthropus: chewing adaptation, postcanine megadontia
• locomotion/posture - adapatations for bipedalism
• relative brain size, not that much larger compared to apes
• body size: smaller than modern humans w/ more sexual dimorph.
• ~3-4 ft tall

Question 3

Australopithecus Discovery

Answer 3

1920s, Raymond Dart
- not accepted b/c of Piltdown Hoax (‘12-‘52)

Question 4

A. afarensis

Answer 4

L: East Africa
T: 3.9 - 2.9 mya

Question 5

A. afarensis findings

Answer 5

“Lucy” - one of the first full skeletons - 3.2 ma

Dikkia, Ethiopia –> recently
- 3.3 mya
- approx. 3 yrs old

Question 6

A. afarensis skull (4)

Answer 6

• sagittal crest
• small brain size
• strong nuchal crest
• relatively prognathic

Question 7

A. afarensis dentition (5)

Answer 7

UJ
- canine further reduced
- posterior tooth rows parallel

LW
- thicker molar enamel (frugivorous & hard seeds)
- slightly larger cheek teeth
- lower 3rd premolar usually bicuspid

Question 8

A. afarensis skeleton (7)

Answer 8

• FM forwardly placed
• lumbar curvature
• short, broad pelvis, curved illium
• valgus knee
• enlarged heel, arches, non-opp. big toe + short toes
• significant sexual dimorph (in gorilla range)

Question 9

A. afarensis arboreal features (3)

Answer 9

• relatively long, curved hand bones
• mobile, upward facing shoulder joints
• rel. long upper limbs vs lower limbs

Question 10

Laetoli findings - A. afarensis

Answer 10

• biped in footprint fossils
• adducted big toe
• dev. of arches
• deep depression of heel

Question 11

Diverse Habitats - A. afarensis

Answer 11

-closed woodland to dry, open grasslands
- ability to walk & climb trees = all the resources

Question 12

Early Australopithecus fossil sites

Answer 12

Ethiopia, Kenya, Tanzania, Chad

Question 13

A. africanus

Answer 13

L: South Africa
T: 3.5 mya - 2 mya

Question 14

A. africanus female traits (4)

compared to afarensis

Answer 14

• slightly enlarged brain & cranial vault
• less prognathism
• less developed nuchal crest
• redacted anterior dentition

Question 15

A. africanus male traits (4)

think about Manny

Answer 15

• cheek bones swept forward
• nasal pillars
• robust mandible
• larger cheek teeth w/ thicker molar enamel

Question 16

A. sediba

Answer 16

L: South Africa
T: 2 mya

Question 17

A. sediba - similarities w/ Aus.

Answer 17

• small brain size
• molar morphology
• small body size
• long upper limbs

Question 18

A. sediba - similarities w/ Homo

Answer 18

• projecting nose
• smaller teeth & chewing muscles
• hand w/ precision grip
• longer legs

Question 19

Paranthropus - major evolutionary trends @ 2.5 mya

Answer 19

hyper-masticatory complex
increase in cheek tooth size
- thick molar enamel
- increase frontal dental reduction & crowding
similar body size to Aus.

Question 20

P. aethiopicis

Answer 20

L: East Africa
T: 2.7 - 2.4 mya

Question 21

P. aethiopicis characteristics

Answer 21

• well developed sagittal & nuchal crests
• prognathism & dish-shaped face
• relatively small brain
• forward zygomatic

Question 22

P. boisei

Answer 22

L: East Africa
T: 2.3 - 1.2 mya

Question 23

P. boisei characteristics (4.4)

Answer 23

• forwardly placed sag. crest
• reduced prognathism
• forward zygomatic
• dental
  a. front crowding
  b. reduction in incisors/canines
  c. thick enamel
  d. increase in pre/molars

Question 24

P. robustus

Answer 24

L: South Africa
T: 2 - 1.5 mya

Question 25

P. robustus characteristics

Answer 25

• ate tough foods, esp. during scarcity
  ^^ P. boisei as well