Australopithecines

826 views
631 views

Published on

some information about Australopithecus species with a short prologue about Ardipithecus species

Published in: Education
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
826
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
57
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Australopithecines

  1. 1. Directed By: Hamed Almasi
  2. 2. Ardipithecus-Lived in 5.8 - 4.4 Mya(the end of the Miocene & beginning of the Pliocene epoch)-Probably ancestral to Australopithecus Afarensis-Brain volume was about the size of a modern chimpanzee-Tim White of Berkeley, the anatomist says:"Ramidus is the first species this side of our common ancestor with chimpanzees."
  3. 3. CHAPTER 1: AUSTRALOPITHECINES MORPHOLOGY-Lived in East and South Africa between 4.4 and 1.4 Mya(The Pliocene & the beginning of Pleistocene epoch)-Trend toward larger brain size-Brain enlargement probably arose in response to changes in foods habitat-Brain volumes ranges from 435 to 650 cc-Between 1.2 to 1.4 m tall-Sexual dimorphism in earlier creature-The normal lifespan was about 25-30 years-Ate meat & plants(friuts.nuts,roots,eggs,lizard,fishs,carrions,...)-Lived with: saber-thoothed tiger,lion,hyraxes,rats,baboons,pigs,monkeys,hippos,...
  4. 4. 1. Change in diet - less “tree” food - more open ground foraging, e.g. seeds, grasses, roots2. Change in dentition - smaller canine teeth - male canines became as small as those of females
  5. 5. CHAPTER 2:AUSTRALOPITHECINES SPECIES Gracile Species Location • Australopithecus Anamensis Kenya • Australopithecus Afarensis Ethiopia & Tanzania • Australopithecus Africanus South Africa • Australopithecus Garhi Ethiopia Robust Species Location • Australopithecus Robustus South Africa • Australopithecus Aethiopicus Kenya • Australopithecus Boisei Kenya Australopithecus BahrelGhazali East Africa Australopithecus Sediba Chad
  6. 6. Gracile Species:3.9 to 2 Mya in East Africa3.5 to 2.3 Mya in South AfricaErect bipeds, about 1-1.5 m. in statureApelike skull morphologyTeeth for chewing food in a hominin fashion
  7. 7.  Earlier fossils show dental features similar to some late Miocene apes; later South African fossils do not Sexually dimorphic, in body size and canine tooth size
  8. 8.  Foramen magnum is forward and downward- looking, as in genus Homo Brain is about a third of a modern human brain in size, and three times larger than Miocene apes Endocasts suggest that the human cerebral reorganization has not yet occurred Blood drainage system for the brain is significantly different from genus Homo
  9. 9. South Africa 1.8 to 1 million years ago Thick bones for their size, with prominent muscle markings Sagittal crest, for huge temporal muscles (more evident in males) – an example of convergent evolution in gorillas and hominins In South Africa the robusts were either an offshoot of the East African lineage, or convergent evolution from a South African ancestor
  10. 10. East Africa 2.5 to 1.3 million years ago More massive skull and larger body size than South African relatives Enormous molars, premolars, mandible and palate East African robust forms likely evolved from earlier gracile forms in east Africa
  11. 11. Chapter 3:Australopithecus Anamensis
  12. 12. Chapter 4:Australopithecus Afarensis
  13. 13. To Homo ? “robust Australopithecines” Australopithecus garhi e.g. Paranthropus (Australopithecus) boisei ? ? ?Australopithecus afarensis Australopithecus africanus Australopithecus anamensis Ardipithecus ramidus
  14. 14. Australopithecus Afarensis Skull
  15. 15. Australopithecus Afarensis Body Ground or tree-dweller?• Slightly curved hand & foot bones• Relatively long and powerful arms• Bowl-shaped pelvis• Knock-kneed (knee joint angled inward)• Heel bone heavily built (like ours)
  16. 16. Anatomical Adaptations forHabitual Upright Bipedalism A comparison of the chimp, human, and A. afarensis femurs demonstrates a rounder femoral head and longer femoral neck length in hominids.
  17. 17. Lucy: first A.Afarensis found
  18. 18. Australopithecus Afarensis Footprints• Laetoli, Tanzania: home to a footprint trail 3.5 m.y. old• Probably a trackway of A. afarensis
  19. 19. An A.Afarensis 3 yrs old baby girl • Ethiopia (Hadar) • Lived 3.3 m.y.ago • Ape-like scapula • Human-like knees • Finger bones partially curved • Heel bone well-developed • Endocast shows delayed brain growth (like us) • Chimp-like hyoid bone
  20. 20. Chapter 5:Australopithecus Africanus
  21. 21. • 3.5 - 2.0 m.y.a.• Mainly S. Africa• Mixture of habitats• Fruit, salads, insects, small easily captured prey• Sexual dimorphism• (male:1.3m&41kg - female:1.1m & 30 kg)• Brain size: 1/3rd ours• Relationship to other hominids? UnknownThis species slightly different from A. afarensis: slightly taller, less facialprognathism, slightly larger brain. Also lived in drier habitats (especially dryscrublands and perhaps open grasslands), and thus may have exploiteddifferent resources.
  22. 22. Chapter 6:Australopithecus Garhi
  23. 23. • 3.0 - 2.0 M.y.a.• Eastern Africa (the site of Bouri, Middle Awash, Ethiopia)• Fruit, salads, insects, small easily captured prey• Brain size: About 450 cc• The dental arcade is U-shaped• link between the genus of Australopithecus and Homo
  24. 24. Chapter 7:Australopithecus Robustus
  25. 25. • 1.9 - 1.2 m.y.a.• Southern Africa• Sexual dimorphism• (male:1.2m&54kg - female:under 1m & 40 kg)• Large sagittal crests, jaws, jaw muscles, and post-canine teeth• Brain size: 410 - 530cc• Teeth were larger and thicker than any Gracile Australopithecus
  26. 26. Chapter 8:Australopithecus Aethiopicus
  27. 27. • 2.7 – 2.5 M.y.a.• Eastern Africa• As tall as A. afarensis• (male:1.5m - female: 1.05m)• Large sagittal crest and zygomatic arch• Brain size: About 410 cc• Ate very tough, grainy foods
  28. 28. Chapter 9:Australopithecus Boisei boisei
  29. 29. NutCracker Man!• 2.3 - 1.2 m.y.a.• Ethiopia, Tanzania, and Kenya in East Africa.• Face is more vertically set, more orthognathic• Low forehead• Foramen magnum located more anteriorly• Sexual dimorphism• (male:1.3m&68kg - female:under 1.05m & 45 kg)• Low vaulted brain case• Brain size: 500- 550cc• The biggest, flattest cheek teeth and the thickest enamel of any known hominin
  30. 30. Chapter 10: Australopithecus Bahrelghazali• 3.5 – 3 M.y.a.• Central Chad in Africa• May be closely related to A.afarensis• Jaw and teeth features to other australopithecines• Probably similar in size to modern chimpanzees• Large incisiform canines and molars• Premolars with 3 roots• Brain size: 400- 550cc
  31. 31. Chapter 11:Australopithecus Sediba
  32. 32. • 1.95 – 1.78 M.y.a.• Southern Africa (South Africa)• brain of the juvenile was human-like in shape,but still much smaller than in Homo specie• generally thinner and lighter jaw, smaller teeth• the legs are quite long• pelvis appears to be more adapted for walking• Brain size: 430 cc
  33. 33. HUMAN EVOLUTION! Finish

×