1 / 67

Primate Evolution (65 - 5 mya)

Primate Evolution (65 - 5 mya). Emergence of Primates. First primates Plesiadapiforms or adapids and omomyids? Environment - Cretaceous to Palaeocene Continental drift (Pangea = Laurasia & Gondwanaland) Success of primates Arboreal theory Visual predation hypothesis (Cartmill 1972, 1992).

afra
Download Presentation

Primate Evolution (65 - 5 mya)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Primate Evolution(65 - 5 mya)

  2. Emergence of Primates • First primates • Plesiadapiforms or adapids and omomyids? • Environment - Cretaceous to Palaeocene • Continental drift (Pangea = Laurasia & Gondwanaland) • Success of primates • Arboreal theory • Visual predation hypothesis (Cartmill 1972, 1992)

  3. Early Primates • Prosimians (65mya) • Monkeys (35mya) • Apes (23mya) • Hominids (5mya)

  4. Early Primates - Traits • Common physical primate traits: • Dense hair or fur covering • Warm-blooded • Live young • Suckle • Infant dependence • Common social primate traits: • Social life • Play • Observation and imitation • Pecking order Common Primate Traits

  5. Continents at the end of the Meszoic Here are the placement of the continents at the end of the Cenozoic and beginning of the Mesozoic, about 65 m.y.a.

  6. Classification of Primates • The primate order is divided into two suborders • The prosimians, or lower primates • include the lemurs, lorises, tarsiers, and tree shrews, • while the anthropoids, or higher primates • include monkeys, apes, and humans

  7. Prosimians • Prosimians are generally small ranging from species the size of a mouse up to those as large as a house cat • They are arboreal, have five digits on each hand and foot with either claws or nails, and are typically omnivorous • They have large, forwardly directed eyes specialized for night vision, hence most are nocturnal • Tarsiers are prosimian primates

  8. Prosimians • As their name impliespro means "before," and simian means "ape”. • prosimians are the oldest primate lineage, and their fossil record extends back to the Paleocene. • During the Eocene prosimians were abundant, diversified, and widespread in North America, Europe, and Asia. • Ring-TailedLemurs are also prosimians

  9. Early Cenozoic Primates • The earliest primates date to the first part of the Cenozoic (65-54 m.y.a.). • The Eocene (54-38 m.y.a.) was the epoch of prosimians with at least 60 different genera in two families. • The omomyid family lived in North America, Europe, and Asia and may be ancestral to all anthropoids. • The adapid family was ancestral to the lemur-loris line.

  10. Eocene Prosimian • Notharctus, a primitive Eocene prosimian; found in North America.

  11. Omomyid An artist’s reconstruction of Shoshonius, a member of the Eocene omomyid family.

  12. Anthropoids • Anthropoids branched off from the prosimians during the Eocene. • Anthropoid eyes are rotated more forward compared to prosimians. • Anthropoids have a fully enclosed bony eye socket. • Anthropoids have a dry nose separate from the upper lip. • Anthropoids have molar cusps.

  13. New World Monkey • New World Monkeys constitute a superfamily belonging to the suborder Anthropoidea (anthropoids)

  14. Old World Monkey • Another superfamily of the anthropoids: the Old World Monkeys

  15. Great Apes • The third superfamily is the great apes, which include gorillas and chimpanzees.

  16. Early Anthropoids • Undisputed remains of early anthropoids date from 34 million years ago; Fayum area southwest of Cairo, Egypt • Found remains from different types of anthropoids, including: • Parapithecids (monkey-like) • Propliopithecids (ape-like) - some believe that the common ancestor for both Old and New World monkeys belonged to this group • Best known of group - Aegyptopithecus which is believed to be after the fashion of the howlermonkey

  17. One of the Earliest Anthropoids • Skull of Aegyptopithecuszeuxis

  18. Miocene Anthropoids • Miocene Period: 24 to 5.2 million years ago • First hominid appeared in Africa where remains have been found dating 5 million years old • Early Miocene Period • Proconsul found in sites in East Africa • Middle Miocene • Kenyapithecus 16 to 10 million years ago with molars resembling modern hominoids • Late Miocene Apes • Movement to Europe and Asia due to warmer weather conditions; migration from Africa • Two main groups: • Sivapithecus - link to orangutans • Dryopithecus

  19. Proconsul A skull of Proconsul africanus from the Kenya National Museum. Proposed appearance of Proconsul africanus.

  20. Kenyapithecus Fossil jaw bones from Equatorius, probably ancestral to Kenyapithecus africanus and K. wickeri.

  21. Sivapithecus • Sivapithecus belongs to the ramapithecid genera along with Gigantopithecus. • Sivapithecus is now believed to be ancestral to the modern orangutan. A Sivapithecus skull.

  22. Gigantopithecus • Gigantopithecus is the largest primate that ever lived, some standing over 10 feet tall and weighing 600 pounds. • Since it died out around 250,000 years ago, it coexisted with Homo erectus. • Some people believe it is still alive today as the yeti and bigfoot. A reconstruction of Gigantopithecus by Russel Ciochon and Bill Muns.

  23. Dryopithecus • Dryopithecus lived in Europe during the middle and late Miocene. • This group probably includes the common ancestor of the lesser apes (gibbons and siamangs) and the great apes. • Dryopithecus has the Y-5 arrangement of molar cusps typical of Dryopithecus and of hominoids.

  24. Oreopithecus • Oreopithecus bambolii lived between 9-7 m.y.a and spent much of its time standing upright and shuffling short distances. • Its big toe splayed out 90 degrees from the other toes. • Oreo is Greek for “mountain”

  25. Early Hominids

  26. Chronology of Hominid Evolution • The Pleistocene (2 m.y.a. to 10,000 B.P.) is the epoch of human life. • Lower Pleistocene (2 to 1 m.y.a.): Australopithecus and early Homo • Middle Pleistocene (1 m.y.a. to 130,000 B.P.): Homo erectus and archaic Homo sapiens • Upper Pleistocene (130,000 to 10,000 B.P.): modern Homo sapiens

  27. Hominid Evolution • Homo habilis(2.0 – 1.6mya) • H. rudolfensis(2.4-1.6mya) • H. erectus (1.9-27kyBP) • H. heidelbergensis(800-100kyBP) • H. neanderthalensis(300-30kyBP) • H. sapiens (130kyBP – present) Scale: Millions of Years BP

  28. The Varied Australopithecines • There are two major hominid genera: Australopithecus and Homo. • However, in 1992 Berhane Asfaw and Tim D. White discovered substantial remains considered to be from hominids ancestral to the australopithecines; these remains have been called Ardipithecus ramidus (thus establishing a third hominid genus) and dated a 4.4 m.y.a. • A more recent (1995, by Maeve Leakey and Alan Walker) discovery has been named Australopithecus anamensis and been dated at 4.2 m.y.a.

  29. Evolution of Bipedalism • Tool use and bipedalism (Darwin/Washburn) • Energy efficiency and bipedalism (Isbell/Young) • Radiator theory (Falk) • Body temperature and bipedalism (Wheeler) • Habitat variability and bipedalism (Potts) • Reproduction and bipedalism (Lovejoy) • Canine reduction and bipedalism (Jolly)

  30. Skeletons Comparison of human and chimpanzee skeletons.

  31. Pelves A comparison of human and chimpanzee pelves.

  32. Dentition Comparison of dentition in ape, human, and A. afarensis palates.

  33. Crania Comparison

  34. New World Monkey Great Ape Hominids show a trend toward a large and internally reorganized brain. An increase in brain size and organization is apparent when comparing the brains of the new world monkey, the great ape, and the human. Human

  35. Sahelanthropustchadensis • Discovered in Chad in 2002 and dated at nearly 7 million years, this skull is presently the oldest known hominid

  36. The Species of Australopithecus • Ardipithecus ramidus 4.4 - ? million years ago • A. anamensis 4.2 - 3.9 • A. afarensis 4.2 - 2.5 • A. bahrelghazali 3.5 - 3.0 • A. africanus 3.5 - 2.5 • P. aethiopicus 2.7 - 2.3 • A. garhi 2.5 - ? • P. boisei 2.3 - 1.3 • P. robustus 2.0 - 1.0

  37. Phylogenetic Tree Phylogenetic tree for African apes and hominids.

  38. Ardipithecus ramidus • Hominid who walked bipedally 4.4 mya • Discovered in 1992 by Tim White in Aramis, Ethiopia (as yet largely unpublished) • Distinct enough to be a new species? • ape-like dentition • bipedal locomotion • overall hominid-like skeleton • small cheek teeth with thin enamel and large canines • arm bones are hominid-like • foramen magnum indicates bipedalism

  39. Australopithecines: Robust or Gracile? • Two species of australopithecines: robust and gracile • Most palaeoanthropologists classify robust species as Paranthropus and gracile species as Australopithecus, although both species are australopithecines. • Gracile • A. anamensis, A. afarensis, A. bahrelghazali, A. africanus, A. garhi • smaller dentition, lighter musculature • Robust • P. aethiopicus, P. boisei, P. robustus • larger teeth, massive jaws, sagittal crest

  40. Australopithecines Skulls of Robust (left) and Gracile (right) Australopithecines.

  41. Australopithecus anamensis • 4.2 - 3.9 mya • average weight - 110 pounds • primitive bipedalism, possibly climbing • found primarily in Kenya • discovered in 1995

  42. 4.2 mya, with oldest definite specimen placed at 3.8 mya apelike features (long arms, prognathic face, toothrow, brain capacity) pelvis, leg, feet, and foramen magnum all indicate bipedalism first discovered by Don Johanson in 1974 and called “Lucy” thought to be the “missing link” until A. anamensis was discovered 20 years later Australopithecus afarensis

  43. Australopithecus afarensis Left: Trail of footprints of A. afarensis made in volcanic ash, discovered by Mary Leakey at Laetoli. Right: Close-up of footprint at Laetoli

  44. Landscape with A. afarensis • Re-creation of a Pliocene landscapeshowing members ofAustralopithecus afarensisgathering and eating various fruits and seeds.

  45. Australopithecus bahrelghazali • 3.5 - 3.0 mya • discovered by Michel Brunet in Bahr el Ghazal, Chad in 1995 • assumed bipedalism (few post-cranial remains)

  46. A. africanus • 3.5 - 2.5 mya • 3.8 - 4.5 feet tall, 55-130 lbs • ape-like tibia, grasping big toes • wide pelvis, parabolic tooth row • primitive bipedalism • first found by Raymond Dart in Taung, South Africa in 1925

  47. Australopithecus garhi • possibly the direct ancestor of early Homo • larger molars than afarensis, but not as large as Paranthropus • lacks enlarged brain of early Homo • toolmaker and butcher • 2.5 mya

  48. Paranthropus aethiopicus • 2.7 to 2.3 mya • earliest robust australopithecine, but least well known • larger dentition, cheek bones, dish-shaped faces, sagittal crests • resembles afarensis but with increases in dental apparatus size • assumed bipedalism • first discovered in Omo, Ethiopia, 1967-1974

  49. The Black Skull - P.aethiopicus The “black skull”, dated to 2.5 m.y.a., was discovered by Alan Walker in 1985 near Lake Turkana.

More Related