first hominins

Question 1

what are hominins? where are lots of the fossils?

Answer 1

• Hominin = only humans and human ancestors

Great rift valley - lots of acessible fossils

Question 2

describe • Sahelanthropus tchadensis

main features? brain size?

Answer 2

• Start to see bipedalism and change in teeth around 6mya
• Chad, central africa
• 6-7 myo - cranium discovered - quite compressed
• Michel bruet
• Foramen magnum - located in the middle - similar to us and chimps
• Likely biped but not 100% confirmed
○ Controversial - some count it as a human ancestor and some do not
• Anatomy
○ Small brain 350 cc
○ Bipedal - foramen magnum
○ Nonhoning chewing
○ Smallish canines
○ Massive brow ridge

Question 3

describe Orrorin tugenesis

Answer 3

tugen hills kenya
6mya
longer neck on femur • No cranium to work with - some post cranal material
• Femur - look at shape and size of a modern one vs orrorin
• Neck was longer and indication of the groove
• Anatomy:
Bipedal - based on femur
tree climber based on hand bones
partially honing canines

Question 4

Ardipithecus !!!! describe how it was found

Answer 4

• Middle awash val project in ethiopia - uncovered lots of fossils
• Back in 1994 - wasn’t until 15 yrs later it published
• 4.4 mya
• Tim white and yohannes haile-selassie (1994)
lived in wooded setting

Question 5

what did they see on ardi?

Answer 5

• Ardipithecus ramidus anatomy
○ Bipedal
○ Based on pelvis, femur, foot
○ Os coxa - similarity, evidence of bipedality
○ Non-honing canines
○ Still small
○ Climbing locomotion based on hand and foot
○ Toes together except for big toe - still used forested environment