Lecture 15 - Hadar

Question 1

Ardipithecus ramidus vs Australopithecus afarensis

Answer 1

ram:
* more canines
* smaller
* lack of chin
* slight nuchal crest
* more prognathism

afarensis:
* limited sagittal crest
* large zygomatic process
* large molars - crushing teeth
* more muscle mass in temporalis - more muscle energy

Question 1

Ar. ram & Au. afarensis in common

Answer 1

• pronounced brow bone
• prognathism
• foramen magnum placed under skull = biped suggestions

Question 2

Au. afarensis general

Answer 2

• East Africa, 3.9-2.9 ma
• Kenya, Tanzania, Ethiopia
• best evidence comes from Hadar, Ethiopia
• includes Lucy skeleton
  “First family” - many individuals died in relatively sudden period of time

Question 3

Au. afarensis cranial

Answer 3

• sagittal crest
• small brain size compared to face
• relatively prognathic
• strong nuchal crest for neck muscle attachments

Question 4

Au. afarensis dental

Answer 4

• reduced canine
• lower 3rd premolar bicuspid
• posterior tooth rows near-parallel
• thicker tooth enamel
• thick enamel suggests diet of nuts, grain, hard fruit pits
• larger cheek teeth

Question 5

Au. afarensis post cranial

Answer 5

pelvis/femur –> human & Lucy versus chimps
chimps are odd ones out

Question 6

Au. afarensis arboreal features

Answer 6

• relatively long and curved hand bones
• highly mobile shoulder joints & upwardly oriented shoulder blade
• relatively long upper limbs compared to short lower limbs

Question 7

Hadar description

Answer 7

extremely close to Aramis, 15 ish miles

Question 8

geology & fauna of Hadar

Answer 8

• from 3.4 to 2.9 ma
• missing time towards the top because of disconformity surface - half a million years
• jump between disconformity surface is a jump between Aust. and Homo
• disconformity surface: evidence of erosion instead of sedimentation –>
  in this case, probably tectonic movement of plates

Question 9

overlap of modern habitats & fossil sites

Answer 9

• Aus. found throughout entire half million section - able to thrive in all types of environments

Question 10

Earliest Homo - Ledi Geraru

Answer 10

• nearby site - earliest evidence for Homo at 2.8 Ma
• environment very open, revealed by fauna

Question 11

Mille Logya

Answer 11

• Barr’s site
• abundant horses & alcelaphin bovids
• very open environment

Question 12

Mosaic habitats

Answer 12

• big pictures that we are trying to find (of habitat), and using little pieces we can understand the bigger picture
• habitat is made up of heterogenous smaller habitats (fresh grass, mossy grass, coniferous trees, alpine vegetation)
• one environment made up of mosaic of smaller habitats
• should be a default expectation that habits are mosaics - not a surprise that habitats back then have different characteristics

Question 13

Hadar vs Aramis

Answer 13

• Hadar is vast temporal and spatial scale compared to Aramis
• A. afarensis capable of living in different environmnets and process different foods - ecological generalist
• Aramis = snapshot (where A. ram found) so don’t know if A. ram has same generalization as A. afarensis