Chapter 7 Flashcards
Taxonomy Chart
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Bipedality
The use of two legs rather than four for locomotion
Bipedal anatomy
A set of anatomical adapations that make it possible for an animal to use two legs for locomotion
Sahelanthropus tchadensis
- Pre Australopith
- Controversial classification as a bidpedal animal or not
- Central Africa
- 7 to 6 mya
Ardipithecus (Ar.) ramidus ramidus
-Pre Australopith
Unusual combination of features:
-Reduction in canine size
-Little sexual dimorphism
-Long arms and curved fingers; grasping foot
-Optional/Facultative bipedalism (bicondylar angle)
-Inefficient bipedalism with aboreal and terrestrial habitats
Australopith (Gracile) Species
- Genera: Australopithecus & Kenyanthropus
- Smaller bodied
- Habitual bipeds
- Long arms, curved fingers
- High degree of sexual dimorhpish
Austrolopith (Robust) Species
- Genus: Paranthropus
- Larger bodied
- Not ancestral to modern humans
- Saggital crest in males
- Post-orbital constriction (gabp)
Australopithecus afarensis (Au. afarensis)
- 3.9 to 3 mya
- Gracile australopith
- High degree of sexual dimorphism
- Habitual biped
- Long arms with curved finger bones
- East Africa
Australopithecus africanus
- Gracile australopith
- South Africa
- 3 to 2.4 mya
- Habitual biped
- Long arms; curved finger bones
- Mixed C3/C4 diets
Paranthropus robustus
- Robust australopith
- 2 to 1.5 mya
- All fossils from South Africa
- Mixed C3/C4 diets
Paranthropus boisei
- Robust austrolopith
- 2.3 to 1.3 mya
- All fossils found in East Africa
- C4 specialist diet
Megadonts
A term sometimes used to refer to Paranthropus because of their flat faces, flairing cheek bones, and extremely large molar teeth.
Osteodontokeratic Culture
A theory proposed by Raymond Dart that Australopiths were tool users or tool makers
- Incorrect b/c site taphonomy concerns
- Australopiths may have shaped bones and horns for digging instruments and termiting sticks
- Lomekwian stone tools (Kenya: 3.3 mya)-choppers and flakes
Characteristics of Bipedalism
- Position of foramen magnum
- Spinal column shows lordosis (s-shape)
- Bowl-shaped pelvis
- Femur at a bycondylar angle
- Locking patella and unequal femoral condyles
- Non divergent big toe and arches
Ideas for orgins of bipedalism:
- free up the hands to carry things
- ability to throw things
- see over tall grasses to spot predators
- efficiency for moving over long distances
- thermoregulation
