Miocene Planet of the Apes Jarðsaga 2 -Saga Lífs og Lands – Ólafur Ingólfsson Háskóli Íslands Available data has been interpreted to suggests that during Miocene 50-100 different species of Hominoid Apes roamed the Old World, compared to 11 species today... But this is not uncontroversial. Other studies suggest ~20 species An article in a 2003 number of Scientific American, “Planet of the Apes”: http://www.chass.utoronto.ca/anthropology/Faculty/Begun/begunSciAm.pdf Hot and debated subject – the origin of Man - http://www.pbs.org/wgbh/evolution/library/11/2/quicktime/e_s_5.html A family tree of primates There are 153 different living species of primates, divided into 6 main groups: • Humans, 1 family, 1 species •Hominoids(“mannapar”), 4 fam., 11 spec. •Oldworldmonkeys(“austur- apar”), 14 fam., 72 spec. •NewWorldmonkeys (“vesturapar”), 16 fam., 33 spec. • Tarsiers (Ghost Monkeys, “draugapar”), 1 fam., 3 spec. • Prosimians (“hálfapar”), 19 fam., 33 spec. Classifying the primates... Hominid - the group consisting of all modern and extinct Great Apes (that is, modern humans, chimpanzees, gorillas and orang-utans plus all their immediate ancestors). Hominin - the group consisting of modern humans, extinct human species and all our immediate ancestors (including members of the genera Homo, Australopithecus, Paranthropus and Ardipithecus). Why did the primates evolve so much during the Miocene? Of particular relevance to the story of primate evolution are the vegetational changes resulting from plate tectonics and formation of mountain ranges. In a cooler and dryer world, grasses flourished in many areas that had previously been forested. A new type of primate—the ground inhabitant— came into being during this period. The generalized nature of the bodily form of primates, combined with their specialized brain, made this critical step possible. The story of human evolution contains numerous question marks – and is constantly being revised... Source of diagram= http://www.amonline.net.au/human_evolution/tree.htm Human ancestry back to Eocene-Oligocene Copyright 2001 VRW A primate known as Propliopithecus (also called Aegyptopithecus), from the Fayum fossil sites of Egypt, is thought to be what the common ancestor of all later Old World monkeys and apes looked like. So Propliopithecus may be considered an ancestor, or closely related to a direct ancestor, of apes, orangutans and humans. Lived 30-40 MY ago... Miocene Primates The Miocene epoch was a remarkable phase in primate evolution in which there appears to have been an increase in the numbers of larger primates that were widely spread throughout the Old World, including Europe, Asia, and Africa. The large number of specimens recovered from widely separated sites over a long period of time has led to taxonomic confusion, and more than 50 species have been described and classified in 20 genera. The large Miocene hominoids appear to belong to three groups, the Sivapithecus, the Dryopithecus, and the Proconsul groups. Within these groups are at least 24 species from Europe, Africa, and Asia. Miocene development of primates • Hominoids evolved during the Miocene epoch (24-5 MY ago). Large ape species originated in Eurasia or Africa by 24-22 MY ago. • Among the oldest known hominoids is a group of apes known by its genus (ættkvísl) name, Proconsul. Species of Proconsul had features that suggest a close link to the common ancestor of apes and humans. The ape species Proconsul heseloni lived in dense forests of eastern Africa about 20 MY ago. It was agile in the trees, with a flexible backbone and narrow chest of a monkey, yet capable of wide movement of the hip and thumb as in apes. Hominoids have no tail. Proconsul heseloni Specimens from Rusinga Island, Lake Victoria, Western Kenya. A primate species restricted to Eastern Africa, 19 - 17 MY ago. Cranial capacity: Smaller than chimpanzee, about 320cc http://www.amonline.net.au/human_evolution/skulls/proconsul.htm Proconsul africanus Proconsul is one of the best represented Miocene hominoid in the fossil record. It lived from ca 23-14 MY ago. Fossils indicate that there was large variation in body sizes, from that of a small monkey (3-5 kg) to that of a gorilla (50-80 kg). They also inhabited a wide range of niches, from open woodlands to rain forests. Their teeth suggest that they were probably fruit eaters. Miocene radiation of large apes • Early in their evolution, the large apes underwent several radiations, periods when species originated and became more diverse. •After Proconsul had thrived for several MY, a group of apes from Africa and Arabia known as the afropithecines evolved around 18 MY ago and diversified into several species. Miocene migration of large apes Apes migrated from Africa to Asia and Europe over a land bridge formed between the Africa-Arabian and Eurasian continents. Later, they migrated back to Africa... Miocene Ape fossil localities It is notable that most fossil sites for Miocene apes are not in Africa, but in Europe and Asia... Fossils of great apes - the large-bodied group represented today by chimpanzees, gorillas and orangutans - have turned up only in western and central Europe, Greece, Turkey, South Asia and China. Eurasia is thus more likely than Africa to have been the birthplace of the family that encompasses great apes and humans, the hominids. Miocene radiation of large apes Around 15 MY ago, two new groups of apes had evolved –thekenyapithecines of Africa and western Asia (first known ~15 MY ago) and the dryopithecines of Europe (first known ~12 MY ago). It is not entirely clear which of these groups of ape species may have given rise to the common ancestor of African apes and humans. Proconsul on the ancestral lineage – but the development is unclear... One view of the lineage... Others favour Dryopithecus • Best known European fossil ape • Middle-late Miocene • Exhibits facial characteristics of African apes and early hominides • Skull resembles skull of infant chimpanzees Dryopithecus broncoi Dryopithecus Several distinct forms of Dryopithecus are known, including small, medium, and large, gorilla-sized animals. In many ways, as might be expected, Dryopithecus is rather generalized in structure and lacks most of the specializations that distinguish the modern apes from modern humans. The canine teeth are larger than those in humans but not as strongly developed as those in modern apes. The limbs were not excessively long—an adaptation in the apes for swinging through the trees. The skull lacked the well-developed crests and massive brow ridges found in modern apes. One commonly held view is that Dryopithecus likely gave rise to the modern gorillas and chimpanzees. Sometime during the Miocene Epoch, the dryopithecines gave rise to a derivative that eventually led to the earliest humanlike forms and finally to humans. Four mid-late Miocene Apes 1. Otavipithecus, (Namibia), middle Miocene (~13 MY) 2.Sivapithecus = orangutan- like ape 17-8 my old from Siwaliks in Pakistan 3. Ankarapithecus (Turkey) is estimated to have first occurred at 10-9.8 MY ago 4. Gigantopithecus (India, China), first occurred 9-6 MY ago Otavipithecus Otavipithecus is an middle Miocene (~13 MY) ape which wasdiscoveredintheAukasMtsinNamibia. Itis considered to be on the linage towards modern apes and humans because of its teeth: They were not specialized (an omnivore) and with thin teeth enamel. Otavipithecus was a small ape, 14-20 kg Sivapithecus, Sivapithecus is thought to be the direct ancestor of ~17-8 MY the orangutan. It is closely related to Ramapithecus, and fossils of the two primates have often been recovered from the same deposits in the Siwalik Hills of northern Pakistan. It was a small-to-medium- sized ape about the size of a modern chimpanzee. The fossil remains of Sivapithecus reveal that it shared many of the same specialized facial features of the orangutan Sivapithecus place in primate evolution was poorly understood until the 1980s. New Sivapithecus finds and the reinterpretation of existing remains convinced most authorities in the 1980s that Sivapithecus was the ancestor of the modern orangutan and diverged from the common lineage of the African apes (i.e., chimpanzees and gorillas) and humans more than 13 MY ago. The earliest Sivapithecus remains found so far are about 17 MY old, and the most recent are about 8 MY old. Ankarapithecus (10-6 MY) • Tectonic movements turned Anatolia into a bridge between Africa, Europe and Asia. Via that bridge, animals which had evolved in Africa walked across and spread to Europe and Asia. • Anatolia was mostly covered by lush forests with grasslands in some places and lakes.This flora was suitable for the elephants, giraffes, rhinoceroses, as well as horses and the tailless big ape, ankarapithecus. Gigantopithecus Gigantopithecus is a large fossil ape, of which two species are known: Gigantopithecus bilaspurensis, which lived 6-9 MY ago in India, and Giganto- pithecus blacki, which lived in China until 200 ka ago. These apes are primarily known from teeth and lower jaw bones. They were large in size, probably much larger than gorillas. They lived in open country and had powerful grinding and chewing teeth. Gigantopithecus blacki Meaning: 'Gigantic Ape of Black' after the 20th century archaeologist Davidson Black. Lived: 6.3 million – 200,000 years ago. Range: South East Asia. Diet: Bamboo, fruits. Size: 300 cm / 550 kg. Jaw and teeth of a Gigantopithecus blacki compared to that of a modern human Gigantopithecus may be the largest primate ever to have walked the Earth. Itfedonbamboointhedenseforests of South East Asia. Gigantopithecus had a broad, short face with a massive jaw and teeth. Like other big herbivores, Gigantopithecus was probably a slow mover. Its feeding habits required it to do little more than move from place to place as it systematically stripped vegetation from its surroundings. Contacts between humans and the Giant Ape... “One intriguing question is what contact our remote ancestor, Homo erectus, may have had with the giant ape.