Exam 3 Flashcards
(52 cards)
What is the difference between relative and absolute dating systems?
Relative dating places fossils or artifacts in a sequence without assigning a specific age; absolute dating provides a numerical age or date.
Which dating technique is most useful for paleoanthropologists?
Argon dating (e.g., potassium-argon) for volcanic layers and older fossils.
Which dating technique is most useful for bioarchaeologists?
Carbon dating (radiocarbon) for organic remains up to ~50,000 years old.
What is stratigraphy used for?
Stratigraphy is useful for both paleoanthropologists and bioarchaeologists as a relative dating method.
How do anatomical traits of hominins differ from non-bipedal apes?
Foramen magnum centered under skull, S-shaped spine, short broad pelvis, angled femur, non-grasping big toe
What are the three types of bipedalism?
Occasional, habitual, obligate.
What is occasional bipedalism?
Used rarely, not main mode (e.g., chimps).
What is habitual bipedalism?
Used regularly but not exclusively.
What is obligate bipedalism?
Only way of walking (e.g., humans).
What are the names of the three known earliest possible hominins?
Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus.
In what time frame did the earliest possible hominins exist?
About 7 to 4.4 million years ago.
On which continent(s) are the earliest possible hominins found?
Africa (Central and East Africa).
How do cranial traits change over time across all hominins?
Face becomes less prognathic, teeth get smaller, brain size increases, dental arch changes from U-shaped to parabolic.
How do postcranial traits change over time across all hominins?
Body size increases, legs get longer relative to arms.
What distinguishes gracile australopithecines from robust australopithecines?
Gracile: Smaller jaws/teeth, lighter build; Robust: Larger jaws/teeth, sagittal crest, heavier chewing muscles.
When and where are gracile australopithecines generally found?
4–2 million years ago, East and South Africa.
When and where are robust australopithecines generally found?
2.7–1.2 million years ago, East and South Africa.
What is the likely diet of gracile australopithecines?
Mixed diet, fruits, leaves.
What is the likely diet of robust australopithecines?
Hard, tough foods like seeds, roots.
What type of bipedalism do australopithecines practice?
Habitual bipedalism, but some climbing ability.
What are the general anatomical traits of genus Homo compared to australopithecines?
Larger brain, smaller teeth/jaws, less prognathic face, more advanced tool use, longer legs.
What are the traits of Homo habilis?
Larger brain (~600–700 cc), smaller teeth, human-like hand.
What is a typical Oldowan/Mode 1 tool?
Simple stone flakes and choppers.
What are the general anatomical traits of genus Homo?
Large brain, rounded skull, small face and teeth, prominent chin (in sapiens), long legs.
