The Tertiary Period. Miocene and pliocene epoch

Miocene and pliocene epoch in total proceeded on the Earth about 18 million years. For Miocene time it is necessary approximately. 12 million years, and on pliocene - 6. From the Pliocene end up to now has driven about 1 million years.

The recession which has begun still in Oligocene of the sea progressively proceeded during all Miocene and pliocene time. The African mainland has received almost modern lineament and was bridged by the bridge to Europe through modern strait of Gibraltar. Europe has been bridged to Asia, and both mainlands lasted on the north much further, than now. The Great Britain was peninsula of Europe. Asia on former remained bridged to the North America, and the North America with Greenland. Australia occupied the isolated position. The ocean a Tethys in a Miocene was very much reduced in the dimension and by only narrow sleeve was bridged through the Krymsko-Caucasian range and Persia to Indian ocean. In a Pliocene the Tethys has broken up to three small isolated the seas - Mediterranean, Black and Caspian.

Orogenic processes have received the big development in a Miocene and even more in a Pliocene. The Alpine, Altay, Sayansk mountains, also Tibet, Pamir and other ridges at this time have risen. The climate became more and more cold. During Miocene time in Europe palm trees have already disappeared. Them have replaced needle-leaved and deciduous trees with falling down leafage. Oaks, maples, elms, poplars, hazels and a magnolia at this time grew. In connection with a climate cold snap during a Miocene epoch herbaceous plants strenuously educed and steppes have received rather a wide circulation. Pliocene vegetation already almost absolutely modern. The sea fauna Miocene - pliocene time was close to the modern. The terraneous fauna of mammals for this season has undergone especially interesting changes. Many of animals of this epoch on a constitution were close to modern, for example entomophagous mammals and bats. However, many animals still in many respects differed from the modern. Gnawers, for example, were far not such, as now, and beavers - approximately in 2 times less modern. Among fundamental the squirrel of figurative gnawers there lived the strange horned animals found in Miocene seams of the North America. But at the same time in forests there were already present sleepyheads, and steppes were populated by customary jerboas. Murine, and also related to porcupines gnawers in a Miocene - a Pliocene were very numerous. Relatives of porcupines after bond of both Americas in a Pliocene were widely settled on all Southern and Central America, and also have inpoured and on modern Vest-Indsky islands. Numerous battleships and already large glyptodonts in a Pliocene dug land the sharp-clawed paws not only in Southern, but also in the North America where they reached width of modern Texas. After glyptodonts to the North America terraneous idlers, by the Pliocene end reached the huge dimensions were relocated also. Last ancient predators - creodontas have died out in the Miocene beginning. All numerous predators of northern mainlands concerned already the present predators. At this time from fundamental dogs arboreal long-tailed raccoons were abjointed. The Bear-dog in Miocene - pliocene time all became larger and larger and by the epoch end have caught up on the dimensions of modern bears.

In the end of a Miocene there lived very interesting predators from whom one on the constitution occupied transitive position between dogs and the present bears, and others - between civet and hyenas.

In a Pliocene on Eurasia the present hyenas and the first bears already ran. Cats, especially saber-toothed - Machairoduses in all Miocene - pliocene time were numerous, as well as martens.

Not artiodactyl during this epoch became less various, than before. Titanothereses, the lophiodontses running and water rhinoceroses have disappeared. But ancestors of the present rhinoceroses, tapirs and horses were increased. Ancestors of horses - parahippuses in the Miocene beginning have left forests and have passed to steppes where they had to run on more hard ground and to eat drier and rigid sterns, than before. In new conditions at meryhippuses, tridactyl ancestors of horses, the middle finger became much stronger lateral which on run lands have already ceased to concern, and bits of dens have gradually become more long and above. From meryhippuses there was in the North America a hipparion - large enough tridactyl horse. Its dens have been arranged, than at modern horses. Hipparions in the end of a Miocene were relocated to Eurasia where they have especially propagated in Miocene - pliocene time. From meryhippuses there were also immediate ancestors of modern horses - pliohippuses and protohippuses. The last, having relocated to the South America, have regenerated there in mountain horses - hippidiums. Since a Miocene in the North America number of rhinoceroses all decreased, and in a Pliocene they have absolutely disappeared. But in the Old World of rhinoceroses was much. Here, along with acerous Aceratherium, in Miocene - pliocene time rhinoceroses, related to modern rhinoceroses of island of Sumatra wandered two-horned Chleiermacher. In the inferior Pliocene there lived monocerous ancestors of the Indian rhinoceros and two-horned ancestors of the African rhinoceroses.

From imparidigitate hoofed animals the Moropus is interesting. This animal, on growth and on addition similar to a horse, but with longer neck, had standing on three dactyls, armed with strong unguises, as at a tiger. The animal could use such feet for pawing or that, having risen on racks, to keep unguises of dactyls for a tree trunk and to incline to itself its branches with juicy leafage. The artiodactyl ruminant reminded on addition of deer. In the beginning of a Miocene they a dog still were acerous, but with the big canines. In the end of a Miocene there were first present deer with simple furcular horns. From a deer of figurative ancestors during Miocene time the first giraffes and the first antelopes - Tragoceros were abjointed. During pliocene time there was a big number of antelopes; many of them on addition were similar to bulls. In the end of a Pliocene lived Leptobos, very close on the constitution to the present bulls. Since a Miocene the American ancestors of camels and llamas consistently became all more largly and more largly. In a Pliocene instead of hoofs at them non-crushing pillows - callosities were standing formed. In this pore camels have passed from the North America to Eurasia, and llamas - to the South America. Pigs in Miocene - pliocene time were numerous. In the Pliocene beginning there were first hippopotamuses, but Anthracoteridaes and huge pigs on the Earth did not exist any more. The South American hoofed animals in a Miocene worried the season of the highest bloom, and only an elephant figurative Pyrotherium have not lived till this time. One South American hoofed animals in a Miocene still remained fine as rabbits, others stilled on the dimensions of bears. Astrapotherium reached the dimensions of large rhinoceroses, Toxodon on magnitude approached tapirs. A horse figurative Litopterna by the form approached horses, and some of them even became monodactylous, but in a Pliocene they have died out, as well as the majority of other South American hoofed animals.

In the beginning of a Miocene from Africa were relocated to Eurasia and successfully here the numerous mastodonts having in a mouth on four tusks (two in the upper jow and two in inferior) have educed. In the end of a Miocene they have inpoured and into the North America. Dens remained bumpy with one mastodonts, as, for example, at halfbeak the mastodont at whom already present long trunk is educed; at other mastodonts dens became edge.

Among a proboscidean Pliocene of India there was an ancestor of the present elephants - the stegodont. Its dens with the big number of crests on the constitution occupied average position between dens of mastodonts and the present elephants. At modern elephants in each half of jow is on one dens which reminds a small millstone and often weighs to 6 kg. Dens at an elephant vary six times during his life. Dens at the stegodont varied the same as and at an elephant: new dens educed behind old and gradually it displaced, so simultaneously in each half of jow of an animal was no more than two dens. The upper tusks at the stegodont big, and inferior absolutely small, disappearing. In the end of a Pliocene first, already present elephants by the ground wandered. At them in a mouth was only one steam of the upper tusks, molars consisted of separate plates, as at modern elephants, instead of from crests. In Miocene - pliocene time together with mastodonts lived still original proboscidean - dinotheres. Some of them were on the dimensions even more elephant. They differed from all other proboscidean themes that had one pair declinate tusks which sat in the inferior jow. Dinothere molars were very simple, edge. Dinothere ate juicy soft feedstuff.

In a Miocene of the South America already there lived ancestors of modern platyrrhine monkeys. In the upper Miocene to Europe on arbours scrambled Pliopithecus - ancestors of gibbons, and dryopithecus - the general ancestors of subhuman primates (a chimpanzee, gorillas) and the person. In India at the same time there were ancestors of orangutans. In a Pliocene subhuman primates were very close to modern descendants as well as numerous ancestors a dog of figurative monkeys already approached on a constitution modern monkeys and baboons.

In Miocene - the pliocene seas of ancient whales did not meet any more. They were changed with new toothed and edentate whales, to a Pliocene assumed a modern air.

Toothed Squalodontidae customary cachalots, narwhals and dolphins gradually displaced. Dolphins in a Miocene were very much halfbeak. To a Pliocene they have assumed a modern air. In the end of a Miocene from edentate whales in the seas the present whales and fin backs floated. Miocene and especially pliocene sea cows (siren) on a constitution approached the modern.