Describe primates
They are agile and adept at grasping, the claws have been replaced by nails, they have stereoscopic vision (the eyes are on the front of the head) they have a reduced sense of smell, and they have a big brain
Arboreal hypothesis
The proposition that primates' unique suite of traits is an adaptation to living in trees
Smith and Jones hypothesized that primates' defining characteristics were adaptation to life in the trees: grasping hands and feet were crucial for holding on to tree branches, binocular vision allowed much rester depth perception for judging distance in
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Visual predation hypothesis
The proposition that unique primate traits arose as adaptations to preying on insects and on small animals
Cartmill proposed his visual predation hypothesis. He he argued that the shift to life in the trees was not the most important factor in explaining primate origins. Rather, the catching of small prey - using both a highly specialized visual apparatus and
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Angiosperm radiation hypothesis
The proposition that certain primate traits, such as visual acuity, occurred in response to the availability of fruit and flowers following the spread of angiosperms
First primates appeared in the early Cenozoic era
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Paleocene epoch
began 66 mya
Eocene
began 56 mya
The Paleocene candidate for the first primates is a highly diverse, highly successful group of primitive mammals called plesiadapiforms
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plesiadapiforms
Paleocene organisms that may have been the first primates, originating from an adaptive radiation of mammals
Plesiadapiforms were probably not primates. They lack key characteristics that define primates today. E.g. lacked a postorbital bar and convergent eye orbits, their digits were not especially ell adapted for grasping tree branches (lacked opposability) th
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Propimates
A separate order of early primate ancestors from the Paleocene, such as the plesiadapiforms
Euprimates
The first true primates from the Eocene: the tarsier like omomyids and the lemur like adapids
Adapids
Euprimates of the Eocene that were likely ancestral to modern lemurs and possibly ancestral to anthropoids
Omomyids
Eocene euprimates that may be ancestral to tarsiers
Euprimates were the most common early fossil primates - accounting for about 40% of all species form that time, or about 200 species
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Unlike the plesiadapiforms, adapts and omomyids had clear primate characteristics: the postorbital bar and convergent eye orbits, long digits with opposability for grasping, digits with nails (not claws), nonspecialized teeth, and a large brain relative t
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Notharctus
A genus of one of the largest adapts from the Eocene
Adapis
A genus of adapts from the Eocene
Adapids - incisors were flat and vertical, pronounced seuxal dimorphism in body size and in canine size, some had lower jaws with two fused halves, some had relatively short foot bones
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Omomyids - large and projecting central lower incisors, small canines, and wide variation in the other teeth, short skull, short and narrow snout, large eye orbits.
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Carpolestes
A plesiadapiform genus from the Paleocene, probably ancestral to the Eocene euprimates
Carpolestes - grasping foot through opposable big toe, long, grasping fingers, nail on the end of first foot digit. May be the link between proprimates of the Paleocene and euprimates of the Eocene
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The extinction of the plesiadapiforms, at the end of the Paleocene, and the appearance of the eupriamtes, at the beginning of the Eocene, coincided with a profound period of global warming.
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A rapid temp increase around 55 mya created tropic conditions virtually everywhere around the world. The resulting creation of new habitats triggered an adaptive radiation of modern appearing primates, the euprimates. In particular, the high global temper
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Many of the euprimates went extinct - some of them may have provided the ancestral base for strepsirhines and haplorhines
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Adapids represent the ancestor group for living lemurs and anthropoids with lemurs evolving a tooth comb and anthropoids not evolving the tooth comb. Their flat incisors, general similarity with a anthropoids, and great diversity suggest that adapts had a
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Strong resemblance between omomyid fossils and living tarsiers and a greater similarity between tarsiers and anthropoids than between lemurs and anthropoids. But, these similarities are more suggestive than definitive.
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Presence of Archicebus in China indicates that haplorhines originated in Asia.
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The Fayum Depression: Heartland of Anthropoid Ancestors
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The parapithecid Apidium was recognized by Henry Fairfield. It was clear that the Fayum was special - it held the record of the first anthropoids. No substantive work occurred there during the next five decades.
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Elwyn Simons concluded that Fayum deserved another look. Simon went to Fayum and during that trip and many more over the next four decades, simons found more than 1, 000 fossils of ancient primates, dating from the late Eocene and early Oligocene. They le
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The teeth morphology indicated that these primates ate fruit and seeds. The Oligocene Fayum primates proved to be the first irrefutable higher primates, with lots of anatomical details to reveal their adaptations
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Apidium
A parapithecid genus from the Oligocene, possibly ancestral to anthropoids
The First Anthropoids
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Basal anthropoids
Eocene primates that are the earliest anthropoids
Eosimias
A genus of very small basal anthropoids from the Eocene
Eosimias's short calcaneus, or heel bone, was like that of an anthropoid.
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Biretia
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Biretia's presence of anthropoid characteristics in the teeth such as the bicuspid lower premolars indicates that this animal too represents the beginnings of higher primates
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The Fayum primates included various strepsirhines and at least three groups of primitive higher primates: oligopithecids, parapithecids, propliopithecids. The oligopithecids were the earliest, dating to about 35 mya. The later parapithecids such as Parapi
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Oligopithecids
The earliest anthropoid ancestors in the Oligocene, found in the Fayum, Egypt
Parapithecids
Anthropoid ancestors from the Oligocene, found in the Fayum, Egypt
Propliopithecids
Anthorpoid ancestors form the Oligocene, found in Africa
Aegyptopithecus
A propliopithecid genus form the Oligocene, probably ancestral to catarrhines; the largest primate found in the Fayum, Egypt
Parapithecids had three pre molars. This condition may directly link parapithecids to platyrrhines, but having three premolars is more likely the ancestral condition that precedes the divergence of platyrrhines and catarrhines
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The propliopithecids consisted of several genera, but tPropliopithecus and Aegyptopithecus, are the most common of this group.
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Propliopithecus had a more derived dental formula of 2120, one fewer premolar tan the parapithecids.
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Aegyptopithecus, the larges tot the fayum primates, had sagittal crest on top of the skull where a large temporal is muslce was attached; brain was small compared to those of later catarrhines; front and hind limbs were equal size - slow moving, arboreal
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Saadanius
An early catarrhine Oligocene genus form a group of primates that gave rise to later catarrhines
Branisella
A south american genus from the Oligocene, ancestral to platyrrhines
the first apes and first monkey originated in the early Miocene, likely between 25 and 30 mya. Two fossil primates illustrate the split, by 25 mya, that led to the emergence of modern apes and modern monkeys
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Aegyptopithecus, the earliest definitive catarrhine, clearly evolved from some anthropoid in the Old World, almost certainly in Africa
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The physical resemblance of Old World monkeys and New world monkeys suggests that platyrrhines originated in Africa, rather than North America. Their mode of reaching South America, however, is still highly debated
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Proconsulids
Early miocene apes found in East Africa
Prconsulids ranged form Micorpithecus, small New World monkeys, and Proconsul, a size of a modern male chimpanzee
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Proconsul is the best known of the early to middle Miocene apes from Africa
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Reflecting the proconsulids' biological diversity, their fossils have been found in a arrange of settings, representing different climates and environments, from open woodlands to tropics. Reflecting these different habitats, their diets varied considerab
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Like Old World monkeys, Proconsul and wrist bones. This direct articulation, a primitive characteristic, indicates relatively limited wrist mobility, whereas living apes have highly mobile wrists for arm swinging and arm hanging.
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Proconsulids' elbows could straighten only so far, whereas living pea' elbows can extend completely.
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The whole package suggests that Proconsul, unlike living apes, walked on the tops of tree branches on all fours. Because these creatures lacked a number of anatomical features that living hominoids share, they can be used as a model of the animals that ga
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Proconsul
This Miocene ape genus was first found in Kenya in 1909 - it was the first fossil mammal ever discovered in that region of Africa. Proconsul literally means "before consul". Proconsul is considered an ancestor to apes, including chimpanzees. The first sku
Proconsulid Body Plan
The body plan of Miocene apes differs form that of modern apes. The Miocene apes had a more monkey like body, with smaller hands, a more restricted hip joint, and a more flexible spine. Modern apes have highly mobile shoulder joints and fully extendable e
This Miocene ape, Proconsul, was half the size of a gibbon
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Dryopithecus
A genus of dryopithecid apes found in southern France and northern Spain
dryopithecids
Early Miocene apes found in various locations in Europe
Dryopithecus, the best known genus within a group of great apes called dryopithecids, lived in the area of Europe that is now France and Spain
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Dryopithecus - larger than earlier apes; resembled living apes in many ways: canines were shape and tusk like; its cheek teeth were long and had very simple chewing surfaces, eel adapted for chewing fruit; teeth enamel indicate that these apes grew slowly
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sivapithecids
Early Miocene apes found in Asia
Sivapithecus
A genus of miocene sivapithecids, proposed as ancestral to orangutans
Sivapithecids were the counterpart of Europe's dryopithecids. The best known is Sivapithecus, an ape ancestor.
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Sivapithecus had thick enameled teeth, adopted for eating hard, tough-textured foods such as seeds. Its robust jawbones were similarly adapted. They are strikingly similar to orangutans, with concave faces, narrow nasal bones, oval eye orbits, projecting
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Gigantopithecus
A genus of Miocene pongids form Asia; the largest primate ever lived.
Gigantopithecus is form Asia - biggest primate - its massiveness would have limited this fossil primate to the ground for all its activities. Had thick enameled teeth and large, thick boned jaws, adapted for eating very hard foods, likely nuts and seeds
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