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Chapter 8. Primate and Hominin Origins. Ancestor to Primates?. What is ancestral to all the critters under the Order Primates ? Where all the humans, australopithicines, monkeys, apes, homo habilis, tarsiers, lorises, aye-ayes, Neandertals, etc. came from…. Primates Review. Me too!.
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Chapter 8 Primate and Hominin Origins
Ancestor to Primates? What is ancestral to all the critters under the Order Primates? Where all the humans, australopithicines, monkeys, apes, homo habilis, tarsiers, lorises, aye-ayes, Neandertals, etc. came from…
Primates Review Me too! *Go back to the chart on pg. 129
The end of the Cretaceous period 65.5 mya Millions of years ago right after the dinosaurs died…
Paleocene 65 myaPlacental mammal radiation • Earliest primates
Eocene 55-35mya More than 200 recognized fossil primate species.
Eocene 55-35 mya Darwinius, from the Messel site in Germany, discovered in 2009 and dates to ~47 mya. More than 200 recognized fossil species.
Eocene Primates Foramen magnum position = whether the body is habitually horizontal (like a horse) or vertical (like a monkey). During the Eocene, the foramen magnum in some primate species was beginning to move from the back of the skull towards the center. Suggesting…Holding their bodies erect while hopping and sitting, like modern lemurs, galagos, and tarsiers.
Oligocene “Rafting” Africa-> South America ~34 mya early in the Oligocene By this early point in the Oligocene, continental drift had separated the New World from the Old World. New and Old World monkeys branch off here, 35 million years ago.
Oligocene Approximate position of the continents during the beginning of the Oligocene
Oligocene Primates from Fayum Walking with the Beasts (BBC) “Whale Killer” • Apidium • Primitive dental arrangement suggests near or before evolutionary divergence of Old and New World anthropoids • Small, squirrel-like fruit and seed eating, adept at leaping and springing
Egypt’s Fayum Today, it’s a ~550 square mile lush “oasis” basin in the desert south of Cairo During the Eocene and Oligocene, the Faiyum was forrested At the beginning of the Miocene, the Faiyum had become a dry hollow
Oligocene Primates from Fayum cont. • Aegyptopithecus (genus) • 35-33 mya • Largest of Fayum anthropoids, roughly the size of a modern howler monkey (13-18 lbs) • Short-limbed, slow-moving
Miocene Hominoid Distribution, From Fossils Thus Far Discovered
Miocene Hominoid Fossils These hominoids are more closely related to the ape-human lineage than Old World monkeys. Mostly large-bodied hominoids, more akin to the lineages of orangutans, gorillas, chimpanzees, and humans. Most of the Miocene forms discovered are so derived that they are probably not ancestral to any living form.
Miocene Fossil Hominoids African forms (23–14 mya) • Especially from western Kenya, these hominoids are, in many ways, primitive. • Proconsul
Miocene Fossil Hominoids European forms (16–11 mya) • From scattered localities in France, Spain, Italy, Greece, Austria, Germany, and Hungary, most are quite derived. • Dryopithecusand Ouranopithecus
Miocene Fossil Hominoids Asian forms (16–7 mya) • The largest and most varied group from Turkey through India/Pakistan and east to southern China, most are highly derived. • Sivapithecus
Sivapithicus • Note the dished face, broad cheekbones, and projecting upper jaw and incisors on both Sivapithecus (left) and the Orangutan (right) Sivapithecus (from Turkey and Pakistan) shows facial features similar to the modern orangutan, suggesting a fairly close evolutionary link.