Miocene 24 5 mya OK here it is the epoch of greatest interest in early primate evolution Major continental locations approx same as today except North and South America Miocene hominoid fossil localities Turnbaugh et al 2002 191 Epoch Geologic Time Scale 1 7 mya 5 mya First hominoids 30 types 24 mya 36 mya Anthropoids proliferate Platyrrhine Catarrhine split Late Eocene anthropoids 55 mya 65 mya Undisputed primates archaic primates disputed Plesiadapiforms http www ucmp berkeley edu cenozoic cenozoic html 22 Feb 2005 Early Miocene 24 16 mya warm and wet Proconsul was abundant in Africa 3 species Probably last ancestor to both Old World monkeys and apes humans the Catarrhines Has teeth like ape but body like monkey At this time see the first hominoids ancestors to apes and humans They had the Y 5 cusp pattern They lived in forests eating leaves and fruit Turnbaugh et al 2002 192 No consensus on first hominoid several different candidates Morotopithecus 20 mya in Uganda mobile shoulder joint for hanging in trees vertebrae suggest short stiff spine Kenyapithecus ca 15 mya in east Africa some include it in Equatorius jaw face teeth have ape like features arm and ankle features Kenyapithecus 4EverEden2 Kenyapithecus 4EverEden2 Darwinsfootsoldier iesabastos The Y 5 cusp pattern is found only among hominoid molars it separates hominoids from Old World monkeys Cercopithecoidea Y 5 cusp pattern hominoid Biological Anthropology 2006 Stanford et al 284 Bilophodont pattern Old World monkeys Middle Miocene 16 10 mya Increasing grassland savannas Few monkey or prosimian fossils Peak of anthropoid proto apes over 20 species Ramapithecid family which includes Orangutan branches off from Dryopithecid family lesser ape great ape human lineages Middle late Miocene apes grouped into two families Ramapithecids Europe Asia Africa Dryopithecids Europe Ramapithecids not thought to be our ancestors At least two genera Sivapithecus and Gigantopithecus Some think Sivapithecus is ancestral to Orangutan 13 mya Sivapithecus Modern orangutan Feder and Park 2007 138 Middle Miocene 16 10 mya Over 13 mya orangutan lineage splits off with Sivapithecus Sivapithecus GSP 15000 from Pakistan Whitehead et al 2005 279 modern Orangutan Turnbaugh et al 2002 193 Dryopithecids Europe Thought to be ancestral to lesser apes and rest of the great apes Gorilla lineage splits off around 8 mya We have very little of the fossil record of gorillas Late Miocene 10 5 mya Terminal Miocene Event cooling trend caused aridity and Africa went from all forest to a lot of grassland This environmental change is seen as significant in the development of the human hominid lineage http www sciencedaily com releases 2013 07 130725125447 htm One Late Miocene ape was Oreopithecus 9 7 mya in Italy Long suspected of being bipedal a 2013 study of its lower spine anatomy indicates it is more like apes and not like bipedal humans Late Miocene 10 5 mya Now Old World monkeys more common than apes probably because could eat leaves Forests shrinking more savanna grasslands 8 4 mya fossil gap when we think hominids split off Fossil gap period during which few fossils exist Where are we finding fossils of early hominids What first set humans apart from apes The earliest human ancestors have a mixture of ape like and human like characteristics The first distinctively human character is bipedal locomotion But the brain remained the size of apes But we are now realizing that the earliest hominids bipedal humans did not all start out exactly like us in terms of locomotion What we see in the beginning of bipedality is a mosaic of characteristics and variety in how these earliest humans are bipedal Omomyids late Eocene 55 mya Peak Eocene 55 36 mya Adapids 36 24 mya Oligocene Propliopithecids Parapithecids Proconsul 24 16 mya Miocene First hominoids 16 10 mya peak 16 10 mya peak Miocene Ca 8 mya gorillas split 6 5 off mya chimps humans split 16 5 mya Ramapithecids including Sivapithecus 13 mya became Orangutan Dryopithecids ancestral to rest of ape human lineage 1 mya 6 5 mya 9 7 mya 13 mya Cladistic tree Based on order of evolutionary branching Remember it is looking as though the last common ancestor between humans and the other great apes and even between humans and gorillas chimps was arboreal NOT knucklewalking
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