More Important Topics of Cylinder

The Holocene Epoch is a geologic period that extends from the present back about 10,000 radiocarbon years. The beginning of the Holocene was punctuated by the Younger Dryas cold period, the final part of Pleistocene epoch. The end of the Younger Dryas has been dated to about 9600 BC

(11550 calendar years BP). However, evidence for the Younger Dryas is not clear cut anywhere other than in the Northern Hemisphere.

The Holocene starts late in the retreat of the Pleistocene glaciers. The Holocene is the fourth and last epoch of the Neogene period (second epoch of the unofficial Quaternary sub-era). The name is derived from the Greek holos (entire(ly)) and ceno (new). It has also been called the "Alluvium Epoch".

Paleontologists have defined no faunal stages for the Pleistocene or

Holocene.

Geology

Continental motions are negligible over a span of only 10,000 years -- less than a kilometer. However, world sea levels rose about 35 meters (110 feet) in the early part of the Holocene due to ice melt. In addition, many areas above about 40 degrees latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 meters over the late Pleistocene and Holocene.

The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea. Holocene marine fossils are known from Vermont, Quebec, Ontario, and Michigan.

Other than higher latitude temporary marine incursions associated with glacial depression, Holocene fossils are found primarily in lakebed, floodplain, and cave deposits. Holocene marine deposits along coastlines are rare because the rise in sea levels during the period exceeds any likely upthrusting of non-glacial origin.

Apart from temporary incursions, Post-glacial rebound in the Scandinavia region resulted in the evolution of the Baltic Sea. The region continues to rise, still causing weak earthquakes across Northern Europe.

Climate

Although geographic shifts in the Holocene were minor, climatic shifts were very large. Ice core records show that before the Holocene there were global warming and cooling periods but climate changes became more regional at the start of the Younger Dryas.

However, the Huelmo/Mascardi Cold Reversal in the Southern Hemisphere began before the Younger Dryas and the maximum warmth flowed south to north from 11,000 to 7,000 years ago. There appears to be a south to north pattern, with southern latitudes displaying maximum warming a few millennia before the Northern Hemisphere regions. It is also possible that the Holocene warming is merely another interglacial period and does not represent a permanent end to the Pleistocene glaciation.

Habitable zones expanded Northwards. Large mid-latitude area such as the Sahara that were previously productive became deserts. The epoch started with large lakes in many areas that are now quite arid.

Animal and plant life did not evolve much during the Holocene, but there were major shifts in the distributions of plants and animals. A number of large animals including mammoths and mastodons, saber tooth cats, and giant sloths disappeared in the late Pleistocene and early Holocene -- especially in North America where common animals that survived elsewhere (including horses and camels) became extinct. Throughout the world, cooler climate ecosystems that were previously regional have been isolated in higher altitude ecological "islands."

Human developments

The beginning of the Holocene corresponds with the beginning of the Mesolithic age in most of Europe; but in regions such as the Middle East and Anatolia with a very early neolithisation, Epipaleolithic is used in place of Mesolithic. Cultures in this period include: Hamburgian, Federmesser, and the Natufian culture.

Both are followed by the aceramic Neolithic (Pre-Pottery Neolithic A and Pre-Pottery Neolithic B) and the pottery Neolithic.

Many types of mammoth lived in temperate and northern climes: the frozen remains of woolly mammoths have been found in the northern parts of Siberia.

Frozen mammoth corpses, when removed from the ice, often prove remarkably fresh: dogs accompanying the finders sometimes ate the flesh. There have been proposals to clone freshly defrosted mammoths in order to revive the species. In addition to occasional frozen mammoths, large amounts of mammoth ivory were found in Siberia, and were an article of

trade for many centuries. It is a common misconception that mammoths were much larger than modern elephants, an error that has led to "mammoth" being used as an adjective meaning "very big". Certainly, the largest known species, the Imperial Mammoth of California, reached heights of at least 4 meters (13 feet) at the shoulder.

However, most species of mammoth were only about as large as a modern Indian elephant, and fossils of a species of dwarf mammoth have been found on Wrangel Island off the east coast of Siberia. They became extinct only at about 2000 BC.

The mammoths diverged from the Asian elephants after the latter group split from the African elephants, meaning that the mammoths were in fact more closely related to the modern Indian elephant than the African elephant is. Since there is a known case in which an Indian elephant and an African elephant have produced a live offspring, it has been theorised that if mammoths were still alive today, they would be able to interbreed with Indian elephants, and this has led to the idea that perhaps a mammoth-like beast could be recreated by taking genetic material from a frozen mammoth and combining it with that from a modern Indian elephant. However, not enough genetic material has been found in frozen mammoths for this to be attempted.

Whether the mammoth died out for climatic reasons or because of overhunting by humans ("overkill") is debated.

There have been claims that the mammoth is not actually extinct, and that isolated herds might survive in the vast and sparsely inhabited tundra of Siberia.

The pilot of a World War II Soviet Union courier plane reported seeing a herd of furry elephants in Siberia in 1944, and some notes compiled by 16th and 17th century Russian travellers recount the hunting of mammoths for their tusks by local tribesmen. However, no solid evidence exists for these claims.

The Plains Zebra (Equus quagga, formerly Equus burchelli) is the most common and widespread form of zebra, once being found on plains and grasslands from the south of Ethiopia right through east Africa as far south as Angola and eastern South Africa.

Because of hunting for meat and hides, and human encroachment on much of their former habitat, Plains Zebras are much less numerous than they used to be, but they remain common in game reserves and by far the most numerous of the three zebra species. Plains Zebras are mid-sized and thick-bodied with relatively short legs. Adults of both sexes stand about 1.4 metres high at the shoulder, are 2.3 metres long, and weigh about 230 kg.

Like all zebras, they are boldly striped in black and white and no two individuals are the same. There are currently three recognised subspecies, plus two further subspecies

which are now extinct.

All have vertical stripes on the forepart of the body, which tend towards the horizontal on the hindquarters. In the north, the stripes are narrower and more defined, southern populations have varied but lesser amounts of striping on the underparts, the legs and the hindquarters. The first subspecies to be described, the Quagga which is now extinct, had plain brown hindquarters. (Technically, because the Quagga was described first as E. quagga, the proper

zoological name for the most common form of the Plains Zebra is E. quagga burchelli.) Plains Zebras are highly social and usually form small family groups consisting of a single stallion, one, two, or several mares, and their recent offspring.

Groups are permanent, and group size tends to vary with habitat: in poor country the groups are small.

From time to time, Plains Zebra families group together into large herds, both with one another and with other grazing species, notably wildebeests.

Unlike many of the large ungulates of Africa, Plains Zebras prefer but do not require short grass to graze on. In consequence, they range more widely than many other species, even into woodland, and they are often the first grazing species to appear in a well-vegetated area.

Only after zebras have cropped and trampled the long grasses do wildebeests and gazelles move in. Nevertheless, for protection from predators, Plains Zebras retreat into open areas with good visibility at night time, and take it in turns to stand watch. They eat a wide range of different grasses, preffering young, fresh growth where available, and also browse on leaves and shoots from time to time.

Description

There are no intact museum specimens of the Dodo extant today. The decaying remnants of the last stuffed Dodo, in Oxford's Ashmolean Museum, were burned in 1755.

Nevertheless, from artists' renditions we know that the dodo had blue-grey plumage, a 23-centimetre (9-inch) blackish hooked bill with reddish point, very small useless wings, stout yellow legs, and a tuft of curly feathers high on its rear end. Dodos were very large birds, weighing about 23 kg (50 pounds).

The breast structure was insufficient to have ever supported flight and it is believed these ground-bound birds evolved to take advantage of an island ecology with no predators.

The traditional image of the dodo is of a fat, clumsy bird, but this view has been challenged by Andrew Kitchener, a biologist at the Royal Museum of Scotland (reported in National Geographic News, February 2002), who believes that the old drawings showed overfed captive specimens.

The Dodo was entirely fearless of people, and this, in combination with its flightlessness, made it easy prey. The name dodo comes from the archaic Portuguese word doudo, meaning "simpleton", doido in modern Portuguese

meaning fool or mad. (The island was first visited by the Portuguese in 1505, but the Dutch were the first permanent settlers on the island.)

There is a persistent myth that dodos were eaten as food for the long voyages between the Cape of Good Hope and Asia, but neither historical nor archeological findings corroborate this. Dodos were hardly ever eaten by the Portuguese, who found the dodos hard to eat and very messy. Dutch records concur. The Dutch settlers called it the Walgvogel ("disgusting bird") for the unpleasant taste and texture of the meat.

No dodo bones have been found in the old middens of the Dutch fort Frederik Hendrik.

However, when humans first arrived on Mauritius, they also brought with them other animals that had not existed on the island before, including pigs, rats and monkeys, which plundered the dodo nests, while humans destroyed the forests where they made their homes.

There is some controversy surrounding the extinction date of the dodo. David Roberts states that "the extinction of the dodo is commonly dated to the last confirmed sighting in 1662, reported by shipwrecked mariner Volkert Evertsz", but other sources suggest 1681.

Roberts points out that because the sighting prior to 1662 was in 1638 (ie 24 years earlier), the dodo was likely already very rare by the 1660s. However, statistical analysis of the hunting records of Isaac Joan Lamotius, carried out by Julian Hume and coworkers, gives a new estimated extinction date of 1693, with a 95% confidence interval of 1688 to 1715.

The last known dodo was killed less than 100 years after their discovery, and no complete specimens are preserved, although a number of museums are home to dodo skeletons.

A Dodo egg is on display at the East London museum in South Africa. Genetic material has been recovered from these and its analysis has confirmed that the dodo was a close relative of the pigeon species that are to be found in Africa and South Asia.

No one took particular notice of the extinct bird, until it was featured in the Caucus race in Lewis Carroll's Alice's Adventures in Wonderland (1865). With the popularity of the book, the dodo became a household word: "as dead as a dodo." The character was named Dodo.

Family Raphidae

Two similar dodo-like species were reported by sailors to be living on islands near Mauritius: in 1613 the Réunion Solitaire, Raphus solitarius on Réunion, and in 1691 the Rodrigues Solitaire, Pezophaps solitarius on Rodrigues. The latter became extinct during the 1760s.

No evidence has ever been found to support the existence of the Réunion Solitaire, and ornithologists now believe that the bird actually seen was the Réunion Flightless Ibis Threskiornis solitarius, which is also now extinct. When it was believed to exist, it was also referred to as 'White Dodo', as travellers' descriptions of the Flightless Ibis correctly gave its plumage as mainly white, and as there exist some paintings of white dodos, it was believed that these showed the assumed dodo of Réunion.

However, at least some descriptions clearly state that wingtips and tail of the Réunion "Solitaire" were black (as it certainly was the case, still seen in its close living relative, the Sacred Ibis), while the paintings show an entirely white bird (apart from what is probably soiling of some feathers with dirt in captivity).

The paintings were most certainly of captive birds in some European menagerie; they show a rounded, not hooked beak which seems to indicate cropping as a precaution against attacks on the keepers (travellers' reports state that, if cornered, dodos would bite quite viciously, as can be expected of a bird with such considerable bulk). The most likely source of the 'White Dodo' paintings is a small number of albinotic dodos - perhaps even only one - that reached Europe and were kept as curiosities.

DNA analysis using the foot of the Dodo and the thigh bone of the Rodrigues Solitaire has recently confirmed that the Dodo and the Rodrigues Solitaire were, as expected, each others closest relative. More surprisingly, the research suggested that these birds were much closer taxonomically to the true pigeons than previously thought, and were particularly close to the Nicobar Pigeon, Caloenus nicobarica.

In 1973, scientists discovered that a species of tree on Mauritius, the dodo tree Sideroxylon grandiflorum = Calvaria major, was dying out. There were only 13 specimens reported left, and all of them were about 300 years old, dating from the time when the last dodo was killed. It was discovered that the dodos ate the seeds of the tree, and only by passing through the digestive tract of the dodo did the seeds become active and start to grow.

After a while, it was discovered that the same effect could be accomplished by letting turkeys eat the seeds. The tree species has been saved. However, more recent research suggests that young specimens were simply overlooked and that it probably was the extinct Broad-billed Parrot Lophopsittacus mauritianus rather than dodos which were chiefly responsible for spreading the seeds. See the dodo tree article for more details and references.

Alleged Modern Dodo sightings

Starting around 1990 or so, people began claiming they saw strange birds on the Mauritius beaches. Although rumors of their survival have gone on for a while, there is no proof of any living dodos. See cryptozoology for more information about cryptids.

ORDER COLUMBIFORMES

Family Raphidae

Mauritius Dodo, Raphus cucullatus

Réunion Solitaire, Raphus solitarius (but see above)

Rodrigues Solitaire, Pezophaps solitarius

Family Columbidae: pigeons and doves

The head and one foot of the Ashmolean dodo, mentioned above, can still be seen in the Oxford University Museum of Natural History.

Literary sightings include a Dodo named Pickwick, pet of Thursday Next, protagonist in the books of Jasper Fforde.

In outward appearance, the Thylacine resembled a large, short-haired dog with a stiff tail, which smoothly extended from the body like that of a kangaroo; several stripes ordered vertically across its hindquarters; and an amazingly large gape. The Thylacine's pouch opened to the rear of its body. The structure of the thylacine spine undergoes a sudden transition about halfway along the body.

The extinct Thylacine at Melbourne Museum, a work of taxidermyIn Tasmania, where there were no Dingos, the Thylacine survived until the 1930s before persecution by farmers, government-funded bounty hunters and, in the final years, collectors for overseas museums saw it wiped out. The last confirmed wild Thylacine sighting was in 1932, and the last captive, named Benjamin, died in the Hobart Zoo on September 6, 1936.

A short black and white film was made of the captive pacing back and forth in its enclosure.

Although there is no reasonable doubt that the Thylacine is extinct, sightings are still occasionally claimed, both in Tasmania and other parts of Australia. In February 2005, a German tourist claimed to have taken digital photographs of a Thylacine, but the authenticity of the photographs has not been established.

In March 2005, Australian news magazine The Bulletin, as part of its 125th anniversary, offered a $1.25 million reward for the safe capture of a live Thylacine. The prize offer closes at the end of June 2005. An offer of $1.75 million was subsequently offered by a Tasmanian tour operator, Stewart Malcolm. No successful claims have been made.

Cloning project

The Australian Museum in Sydney began a project in 1999 reminiscent of the science fiction movie Jurassic Park.

The goal is to use genetic material from specimens taken and preserved in the early 20th century to clone new individuals and revive the species from extinction. In late 2002 the researchers had some success as they were able to extract usable DNA from the specimens.

On February 15, 2005, the museum announced that it was stopping the project after tests showed the specimens' DNA had been too badly degraded by the (ethanol) preservative.

In May 2005, Professor Mike Archer, the University of New South Wales' Dean of Science and former director of the Australian Museum, announced that the project was being restarted by a group of interested universities and a research institute.

It was much larger than its cousins, Smilodon fatalis and Smilodon gracilis, possessing a massive chest and front legs.

This great cat stood 120 cm at the shoulder, larger than the largest modern cat, the Tiger. The Smilodon populator likely hunted in groups, because of its large leg muscles and stocky posture, it could not run fast enough to catch prey, so it would travel with others in order to ambush small grass-dwelling animals.

It would then restrain the animal with its large leg muscles, and fatally slice it at the throat with its saber teeth which were sometimes as large as 18 cm (7 inches) long. These large canines were rather fragile, and could not be used unless the prey was held down (this was almost undoubtedly

the use of the heavily muscled forearms). Fossils have been found of several Smilodon populator in a close vicinity, with one grass-dwelling animal near them, which gives further proof for the social Smilodon theory.

This plant-eater was about 11 feet (3.5 m) long. It had two horns on its snout, the lower one larger than the one between its eyes (about 3 feet (1 m) long). It had long hair, small ears, short, thick legs, and a stocky body.

It was hunted by early humans, who probably caused its extinction. Its shape was known from prehistoric cave drawings until a completely preserved specimen (missing only the fur and hooves) was discovered in a tar pit in Starunia, Poland. The specimen, an adult female, is now on display in the Polish Academy of Science Museum of Natural History in Krakow. Recent carbon dating has shown that populations survived as recently as 8,000 B.C. in Western Siberia A close relative, the Sumatran Rhinoceros (Dicerorhinus sumatrensis), still survives in South-East Asia, but is highly endangered.

A large and heavy mammal, it could probably only have moved one or two miles per hour.

Glyptodons were covered by a protective shell composed of more than 1,000 one inch-thick bony plates, called osteoderms or scutes. Each species of glyptodont had its own unique osteoderm pattern and shell type. With this protection, they were armored like turtles, but unlike most turtles, could not withdraw their heads, so they developed a bony cap on the top of their skull.

Even the tail of Glyptodon had a ring of bones for protection. The nasal passage was reduced with heavy muscle attachments for some unknown purpose. Some have speculated that the muscle attachments were for a proboscis, or trunk, much like that of a tapir or elephant. However, most animals with a trunk have nasal bones receding back on the skull, and glyptodons do not have this feature.

The lower jaws were very deep and helped support massive chewing muscles to help chew the coarse fibrous plants that can be found along river and lake banks.

Glyptodons originated in South America and first appeared in the American Southwest after North and South America connected at the Isthmus of Panama, about 2.5 million years ago. They became extinct about 10,000 years ago.

The Pleistocene Epoch is part of the geologic timescale, usually dated as 1.8-1.6 million to 10,000 years before present, with the end date expressed in radiocarbon years. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold. The end of the Younger Dryas has been dated to about 9600 BC (11550 calendar years BP).

The GSSP for the start of the Pleistocene is in a reference section at Virca in Italy that has unresolved dating ambiguities.

The Pleistocene follows the Pliocene epoch and is followed by the Holocene epoch. The Pleistocene is the third epoch of the Neogene period or 6th epoch of the Cenozoic era.

The end of the Pleistocene corresponds with the end of the Paleolithic age used in archaeology.

Pleistocene dating

As with other older geologic periods, the rock beds that define the start of the Pleistocene are well identified, but the exact dates of the start and end of the period are slightly uncertain. To cover the recent period of repeated glaciations, however, the start was set too late and some early cooling and glaciation are now set in the Pliocene. Some would prefer a start date of around 2.5 million years BP.

Pleistocene paleogeography and climate

The maximum extent of glacial ice in the north polar area during Pleistocene time.The modern continents were essentially at their present positions during the Pleistocene, probably moving no more than 100km. The Pleistocene climate was characterized by repeated glacial cycles where continental glaciers pushed to the 40th parallel in some places. Four major glacial events have been identified, as well as many minor intervening events.

The four major identified glacial excursions were the Nebraskan-Gunz, Kansan-Mindel, Illinoian-Riss, and Wisconsin-Würm. There may have been as many as 14 additional unnamed advances whose results have been largely erased by the later glaciers. Each glacial advance tied up huge volumes of water in continental ice sheets 1500-3000 meters thick, resulting in temporary sea level drops of 100 meters or more. Antarctica was ice-bound throughout the Pleistocene as well as the preceding Pliocene.

Pleistocene fauna

There are no faunal stages defined for the Pleistocene or Holocene. Both marine and continental faunas were essentially modern. It is believed by most scientists that humans evolved into modern man during the Pleistocene. Major extinctions of large mammals, including mammoths, mastodons, saber-toothed cats, glyptodons and Ground sloths, started late in the Pleistocene and continued into the Holocene. The extinctions were especially severe in North America where native horses and camels were eliminated.

Pleistocene deposits

Pleistocene continental deposits are found primarily in lakebeds and caves as well as in the large amounts of material moved about by glaciers. Pleistocene marine deposits are found primarily in areas within a few tens of kilometers of the modern shoreline. In a few geologically active areas such as the Southern California coast, Pleistocene marine deposits may be.

Some cryptozoologists have investigated reports of megatheria surviving in South America. In the 1890s an

Argentinean explorer, geographer and adventurer, Ramon Lista, was hunting in a portion of his country, known as Patagonia, when a large, unknown creature covered with long hair trotted past his party. To Lista, the creature looked like a gigantic armadillo. The party shot at the beast, but the bullets seemed to have no effect.

Professor Florentino Ameghino, a paleontologist in Argentina, heard the Lista story and began to wonder if the strange beast was a giant sloth that had somehow survived till the present day. He might not have put much stock in the Lista story if it had not been for the legends he had collected from natives in the Patagonia region about hunting such a large creature in ancient times.

The animal in the stories was nocturnal, and slept during the day in burrows it dug with its large claws. The natives also found it difficult to get their arrows to penetrate the animal's skin. Ameghino, furthermore, had a piece of physical evidence:

A small section of apparently fresh hide found by a rancher named Eberhardt on his property in a cave in 1895.

The hide was studded with small, hard, calcium nodules and would have been impervious to the teeth of many predators.

It seemed likely that it would have also resisted native arrows, along with Lista's bullets.

So sure was Ameghino this was the creature Lista had seen, he decided to name it after him: Neomylodon listai, or "Lista's new Mylodon."

Expeditions to Eberhardt's cave and other caves soon recovered additional pieces of hide. With the development of the debated Carbon-14 dating method in the twentieth century, the age of the Mylodon remains in the Eberhardt's cave was apparantly settled. In short, the skin was estimated to be roughly 11,000 to 5,000 years old. Conditions in the caves may have preserved the skin, making it look fresh to the eye and fooling Ameghino. No additional evidence has turned up that the giant sloth survives today.

The corporal mass was 250 kilos. As the "Ursidos" in general, Arctotherium was omnivorous. The teeth reflects this wide diet, with short not specializing, canine incisor teeth.

It was a herbivore, which was gathering the meal on the banks of the marshes or cause fluvial. The estimated mass was 2.5 to 3 tons.

With a 3 meters of length and a mass of 1 ton. The cranium of this animal has a size of 70 centimeters.

They lived in Europe and Asia.

The Pliocene epoch is the period in the geologic timescale that extends from 5.3 million to 1.8 million years before present.

The Pliocene follows the Miocene epoch and is followed by the Pleistocene epoch. The Pliocene is the second epoch of the Neogene period.

As with other older geologic periods, the rock beds that define the start and end are well identified, but the exact

dates of the start and end of the epoch are slightly uncertain. The Pliocene was named by Sir Charles Lyell. The name means roughly "continuation of recent", and refers to the essentially modern mammalian faunas.

The Pliocene boundaries are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pliocene. The upper boundary was intended to be set at the start of the Pleistocene glaciations but is now considered to be set too late.

Pliocene subdivisions

The Pliocene faunal stages from youngest to oldest are:

Gelasian (2.588 – 1.806 MYA)

Piacenzian (3.600 – 2.588 MYA)

Zanclean (5.332 – 3.600 MYA)

Pliocene climate

Climates became cooler and drier, and seasonal, similar to modern climates. Antarctica became ice-bound near or before the start of the Pliocene. Mid-latitude glaciations were probably underway before the end of the epoch; the Arctic ice cap formed, and Antarctica was covered entriely with year-round glaciation by the end of the period.

Pliocene paleogeography

Continents continued to drift toward their present positions, moving from positions possibly as far as 250km from their present locations to positions only 70 km from their current locations. South America became linked to North America through the Isthmus of Panama during the Pliocene, bringing a nearly complete end to South America's distinctive marsupial faunas. The formation of the Isthmus would have major consequences on global temperatures, as warm equatorial ocean currents were cut off and an Atlantic cooling cycle began, with cold Arctic and Antarctic waters dropping temperatures in the now-isolated Atlantic ocean.

Africa's collision with Europe formed the Mediterranean Sea, cutting off the Tethys Ocean.

Sea level changes exposed the land-bridge between Alaska and Asia.

Pliocene marine rocks are well exposed in the Mediterranean, India, and China. Elsewhere, they are exposed largely near shores.

Pliocene flora

The change to a cooler, dry, seasonal climate had considerable impacts on pliocene vegetation, reducing tropical species world-wide. Deciduous forests proliferated, coniferous forests and tundra covered much of the north, and grasslands spread on all continents (except Antarctica). Tropical forests were limited to a tight band around the equator, and in addition to dry savannahs, deserts appeared in Asia and Africa.

Pliocene fauna

Both marine and continental faunas were essentially modern, although continental faunas were recognizably a bit more primitive than today. The first recognizable primitive humanoid ancestors appeared in the late Pliocene.

The land mass collisions (between Africa and Eurasia; formation of the Panamanian Ismuth between North and South America, and the land bridge between Asia and North America) meant great migration and mixing of previously isolated species.

Herbivores got bigger, as did specialized predators.

Mammals

In North America, rodents, large mastodonts and gomphotheres, and opossums continued successfully, while hoofed animals (ungulates) declined, with camel, deer and horse all seeing populations recede. Rhinos, tapirs and chalicotheres went extinct. Carnivores including the weasel family diversifed, and dogs and fast-running hunting bears did well. Ground sloths, huge glyptodonts and armadillos came north with the formation of the Panamanian Isthmus.

In Eurasia rodents did well, while primate coverage declined. Elephants, gomphotheres and stegodonts were successful in Asia, and hyraxes migrated north from Africa. Horse diversity declined, while tapirs and rhinos did fairly well. Cows and antelopes were successful, and some camel species crossed into Asia from North America. Hyaenas and early sabre-toothed cats appeared, joining other predators including dogs, bears and weasels.

Africa was dominated by hoofed animals, and primates continued their evolution, with australopithecines (some of the first hominids) appearing in the late Pliocene. Rodents were successful, and elephant populations increased. Cows and antelopes continued diversification and overtaking pigs in numbers of species. Early giraffes appeared, and camels migrated via Asia from North America. Horses and modern rhinos came onto the scene. Bears, dogs and weasels (originally from North America) joined cats, hyaenas and civets as the African predators, forcing hyaenas to adapt as specialized scavengers.

South America was invaded by North American species for the first time since the Cretaceous, with North American rodents and primates mixing with Southern forms. Litopterns and the notoungulates, South American natives, did well. Small weasel-like mustelids and coatis, carnivores both, migrated from the north. Grazing glyptodonts, browsing giant ground sloths and smaller armadillos did well.

The marsupials remained the dominant Australian mammals, with herbivore forms including wombats and kangaroos, and the huge diprotodonts. Carnivorous marsupials continued hunting in the Pliocene, including dasyurids, the dog-like thylacine and cat-like Thylacoleo. The first rodents arrived, while bats did well, as did ocean-going whales. The modern duck-billed platypus, a monotreme, appeared.

Birds

Pliocene oceans

Oceans continued to be relatively warm during the Pliocene, though continued cooling. The Arctic ice cap formed, drying the climate and increasing cool shallow currents in the North Atlantic. Deep cold currents flowed from the Antarctic. The Pliocene seas were alive with sea cows, seals and sea lions.

Hipparion Rocinantis Crusafonti

The evolutionary stages of the horse (family Equidae) serve as an excellent illustration of the evolutionary process because it allows us to observe a step-by-step change in the shape of the bodies, the build of the limbs, and the structure of the teeth.

In accordance with the changes in the environment, development continued from a five-toed mammal the size of a fox, to the single-hoofed, modern-sized horse we see today. At the beginning of this evolutionary line, it is very difficult to distinguish the ancestors of horses from the ancestors of tapirs and rhinoceroses. Both of these animals have obviously similar origins and similarities in the structure of their teeth, odd-toed limbs, obvious mobility of the upper lip, and other aspects by which they join the evolutionary line of odd-toed, hoofed mammals, the Perissodactyls.

The tapirs and rhinoceroses remained adapted to their original style of life, conserving forms suitable for life in tropical forests, but the evolutionary line of the horse adapted to life on dryer land in the much-harsher climatic

conditions of the steppes. The first ancestors of the modern horse walked on several spread-out toes, an accommodation to life spent walking on the soft, moist grounds of primeval forests. As the mainland was drying out, the steppes began to appear, and with it came large numbers of dry land predators. This in turn required the horse’s predecessors to possess more speed in order to survive.

The ability to run faster was accomplished by the lengthening of limbs and the lifting of some toes from the ground in such a way that the weight of the body was gradually placed on one of the longest toes, the third. On solid ground, pushing-off with a single toe and equipped at the last evolutionary link with a hoof, the horse was able to reach fast speeds. The modern horse is a single-toed, hoofed mammal, while his predecessors were multi-odd-toed animals.

The evolutionary development of the odd-toed predecessors to the present single-toed Family Equidae can be observed in the Tertiary period of North America, where layers of many well-preserved fossil skeletons of horse predecessors have been discovered. Paleontologists have been able to piece together a more complete picture of the modern horse’s evolutionary line than of any other mammal species.

The evolutionary line of horses began in the lower Eocene epoch in a form called Eohippus. This “horse” was approximately the size of a fox and had various characteristics reminding us of its older predecessors: a relatively short head, 44 teeth with uneven, dull and bumpy molars, a short neck, a “springy”, arched back, and “wrist” and hock joints that are still low to the ground.

The limbs are relatively long, obviously showing the beginnings of adaptation to gaining more speed. The forelimbs had developed five toes out of which only four were equipped with a small hoof; the fifth large “toe–thumb” was off the ground. The hind limbs had three out of the five toes equipped with small hooves, while the first and fifth toes did not touch the ground.

During the Eocene, the Eohippus branched out into various types resembling the fox, mainly in size (from 250 mm to 450 mm in height). Thousands of complete, fossilized skeletons of these animals have been found in the Eocene layers of North America, mainly in the Wind River basin of Wyoming. Similar limbs of four-toed horse ancestors have also been discovered in the Eocene layers of Europe. This mammal was called Hyracotherium.

Orohippus, the successor of Eohippus, appeared in the middle of the Eocene. It has also been called Protorohippus. It still very much resembled the Eohippus; same size, slimmer body, elongated head, slimmer forelimbs and longer hind legs, all of which are characteristics of a good jumper. The outer toes of Eohippus are no longer present in the Orohippus; hence on each forelimb there were four fingers (toes) and on each hind leg three toes, and the first of his premolar teeth were dwarfed.

In the early stages of the Oligocene epoch, the North American environment was changing. During the still-warm and dry weather conditions, the forests were yielding to flatlands, which were home to grasses and various kinds of brush. In some places these plains were covered in sand; hence the type of environment resembling our present prairies.

The younger Pliocene epoch revealed the Mesohippus, which was one of the more widespread types of mammals in North America at the time. Mesohippus walked on three toes (fingers) on both front and hind feet. The third toe was stronger than the outer ones and thus more weighted. Although the first and fifth toe remained, they were very small. Judging by its slim limbs, Mesohippus, which was about 500 mm tall, was a fast animal.

At the end of Oligocene epoch and the beginning of the Miocene epoch, the Mesohippus evolved into a form known as Miohippus. Miohippus had some parts bigger than its predecessor. It had branched out into two branches from which one adjusted to the life in the primeval forests, while the other remained suited to life on the prairies. The forest form led to the birth of Kalobatippus (Miohippus intermedius), whose second and fourth finger again elongated for travel on the softer primeval forest grounds.

The Kalobatippus managed to relocate to Asia via the Bering Strait land bridge, and from there moved into Europe, where its fossils were formerly described under the name Anchitherium. Kalobatippus is then believed to have evolved into a form known as Hyohippus, which became extinct near the beginning of Pliocene.

From the Miohippus that remained on the steppes evolved the North American breed of Parahippus. This little “horse” was the size of a small pony, with a prolonged skull and the facial structure resembling horses of today. The third toe became stronger and larger, hence carrying the main weight of the body. His four premolars resembled the molar teeth and the first almost disappeared. The incisive teeth of the Parahippus, like its predecessors, had a crown as humans do; however, the top incisors had a trace of shallow crease marking the beginning of the core/cup.

In the middle of the Miocene epoch, Merychippus appeared, following after the Parahippus. Meryhippus’ “crunching” on hard steppe, grassy plants caused it to grow relatively longer. It also had wider molars than its predecessors. The hind legs, which were relatively short, still had the side toes equipped with small hooves, though they probably only touched the ground when running. From the numerous varieties of Meryhippus evolved three new kinds of equids: Hipparion, Protohippus and Pliohippus.

According to shapes, the most diverted of the three was the Hipparion. The main difference here was in the structure of tooth enamel. In comparison with other horses, the inside, or tongue side had a completely isolated parapet. On his slim legs, the Hipparion had three toes equipped with small hooves, but the side toes did not touch the ground. The American Hipparion, also known as Neohipparion, proliferated in several kinds of equids several of which managed to migrate to Asia and Europe during the Pliocene Epoch. (The European Hipperia differs from the American Hipparion in the smaller body size – the most known discovery of these fossils was near Athens.)

The complete and well-preserved skeleton of the North American Hipparion shows an animal the size of a small pony. They were very slim, similar to antelopes, and equally timid. They easily adjusted to life on dry prairies. According to newer research, they’re being excluded from the direct ancestry of horses, as it’s believed Hipparion more likely led to the evolution of zebras and asses. Outside the diversities of head features, today’s horses, asses, and zebras differ only slightly in their teeth and bones.

The branch of Protohippus that is believed to be the line leading to the modern horse died off in the Pliocene. The form of Meryhippus that lead to present horses was the Pliocene Pliohippus. It still had long extra toes on both sides of the hoof, but they were externally barely visible, callused stubs. The long and slim limbs of Pliohippus reveal a quick-footed steppe animal. The Pliohippus became the Plesippus, and further evolution into the form of genuine Equus occurred during the upper Pliocene.

It still remains uncertain how these horses came from their “home land” of North America to Europe.

At the end of the Pliocene, the climate in North America began to cool down significantly. The animals were forced to move south. One part of the Plesippus species escaped to South America, and the other moved across the land bridge around the Bering Strait into Asia and Europe. A portion also remained in the southern section of North America. The Ice Age spread five times over Europe and North America and five times again receded (the interglacial periods). This of course lasted many millennia and it is estimated that approximately one million years elapsed from the Ice Age (the Quaternary period) to our era.

The oldest species of true horse, Equus stenonis, was discovered in Italy, and is believed to have evolved from the Plesippus at the end of the Tertiary and beginning of the Quaternary periods. Equus stenonis suddenly proliferated into two branches, one lighter in body mass and one heavier. The North American genuine form of the diluvium horse was named Equus scotti and did not differ in any way from the European form; however, some types exceeded the modern horse (Equus scotti var. giganteus) in size.

In South America the Plesippus was evolving into a form named Hippidium. The Hippidium was relatively short-legged with an especially long nose that also formed the lower part of the skull. It continued to live on the South American pampas for a long time, but eventually died off. All the horses in North America became extinct as well, but more likely due to some mass contagion.

Horses in Historical Times

At the end of the 15th century, when the first Europeans came to America, there were no horses; the cultural tribes of Indians (in today’s Mexico and Peru) did not even have a name for the animal. The Spanish imported predecessors of all the horses back to America. Runaway horses and cattle went wild on the pampas and proliferated into large herds, only to be caught again later and domesticated.

Emergence of the Genuine Equus Species

The species of genuine horse came to walk only on the end of the third toe and from both side toes, as did their predecessors. Skeletal remnants of show obvious wear on the back of both sides of metacarpal and metatarsal bones, commonly called the “splint bones”. They are the remnants of the second and the fourth toe. It is often believed that the splint bones on the modern horse are a useless attachment, but they indeed play an important role in supporting the carpal joints (front knee) and even the tarsal joints (hock).

It is not unheard of that foals are occasionally born with three toes equipped with hooves. This is called a phylogenetic atavism caused by arrested development in a certain embryonic stage.

Throughout the phylogenetic development, the teeth of the horse underwent significant changes. The type of the original omnivorous teeth with short, "bumpy" molars, with which the prime members of the evolutionary line distinguished themselves, gradually changed into the teeth common to herbivorous mammals. They became long (as much as 100 mm), roughly cubical molars equipped with a flat grinding surface. In conjunction with the teeth, during the horse’s evolution the elongation of the facial part of the skull is apparent, and can also be observed in the backward set eyeholes.

In addition, the relatively short neck of the equine ancestors became longer with equal elongation of the legs.

This is because they were forced to find food by grazing on the steppes. Finally, the size of the body was grew as well, not only due to plentiful food, but also to the increase in variety.

The horns looked alike very much to the actual deer, but the helmets, tail and bony structure do not leave doubts of the origem. For its habits is clear that they were living in herds where the biggest males were disputing territories and harems. Scientific name: Climacoceras Gentryi. Epoch: Pliocene. lived in Africa. weight: Next to 100 kg. Height: 1.5 m

Probably giraffe family evolved of the Climacoceras; Canthumeryx, Paleomeryx and Paleotragus. From this point of the time in forward, the linage of the giraffe evolved towards the Sivatherium (at the end of the Miocene) and later it evolved towards the okapi - an actual mammal that lives from the Miocene.

The height was similar to that of a contemporary "dun bear ". The corporal mass was near 250 kilos. As the "Ursidos" in general, his feeding was omnivorous and she was eating of everything, from small mammals, fish, insects, eggs, fruits, carrion and moribund animals.

His teeth reflects this wide diet, with short not specializing, canine and circular incisor teeth, limited premolars, molars. They lived in Argentina.

Flatter than a Volkswagen Beetle, but about the same general size and weight, the glyptodon (or glyptodont) is

believed to have been a herbivore, grazing on grasses and other plants found near rivers and small bodies of water. A large and heavy mammal, it could probably only have moved one or two miles per hour.

Glyptodons were covered by a protective shell composed of more than 1,000

one inch-thick bony plates, called osteoderms or scutes. Each species of glyptodont had its own unique osteoderm pattern and shell type. With this protection, they were armored like turtles, but unlike most turtles, could not withdraw their heads, so they developed a bony cap on the top of their skull. Even the tail of Glyptodon had a ring of bones for protection.

The nasal passage was reduced with heavy muscle attachments for some unknown purpose. Some have speculated that the muscle attachments were for a proboscis, or trunk, much like that of a tapir or elephant. However, most animals with a trunk have nasal bones receding back on the skull, and glyptodons do not have this feature. The lower jaws were very deep and helped support massive chewing muscles to help chew the coarse fibrous plants that can be found along river and lake banks.

Glyptodons are part of the placental group of mammals known as Xenarthra. This order of mammals includes anteaters, tree sloths, extinct ground sloths, and armadillos.

Predators of the glyptodon could have included the sabre-toothed tiger, although this predator would likely have struggled to turn the 1 to 2-ton animal over to reach its unprotected belly.

Glyptodons originated in South America and first appeared in the American Southwest after North and South America connected at the Isthmus of Panama, about 2.5 million years ago. They became extinct about 10,000 years ago.

It was much larger than its cousins, Smilodon fatalis and Smilodon gracilis, possessing a massive chest and front legs. This great cat stood 120 cm at the shoulder, larger than the largest modern cat, the Tiger.

The Smilodon populator likely hunted in groups, because of its large leg muscles and stocky posture, it could not run fast enough to catch prey, so it would travel with others in order to ambush small grass-dwelling animals.

It would then restrain the animal with its large leg muscles, and fatally slice it at the throat with its saber teeth which were sometimes as large as 18 cm (7 inches) long.

These large canines were rather fragile, and could not be used unless the prey was held down (this was almost undoubtedly the use of the heavily muscled forearms). Fossils have been found of several Smilodon populator in a close vicinity, with one grass-dwelling animal near them, which gives further proof for the social Smilodon theory.

The Miocene epoch is a period of time that extends from about 23 to 5.3 million years before the present. As with other older geologic periods, the rock beds that define the start and end are well identified, but the exact dates of the start and end of the period are uncertain. The Miocene was named by Sir Charles Lyell and the name means roughly

"less recent", referring to a period encompassing the essentially modern mammalian faunas. The Miocene follows the Oligocene Epoch and is followed by the Pliocene Epoch. The Miocene is the first epoch of the Neogene period.

The Miocene boundaries are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Oligocene and the cooler Pliocene.

Miocene Subdivisions

The Miocene faunal stages from youngest to oldest are:

Messinian (7.246 – 5.332 MYA)

Tortonian (11.608 – 7.246 MYA)

Serravallian (13.65 – 11.608 MYA)

Langhian (15.97 – 13.65 MYA)

Burdigalian (20.43 – 15.97 MYA)

Aquitanian (23.03 – 20.43 MYA)

The subdivisions within the Miocene are defined by the relative abundance of different species of calcareous nanofossils (calcite platelets shed by brown single-celled algae) and foraminifera (single-celled protists with diagnostic shells).

Miocene Climate

Climates remained moderately warm although slow global cooling that eventual led to the Pleistocene glaciations continued.

Miocene Paleogeography

Continents continued to drift toward their present positions. Of the modern geologic features, only the land bridge between South America and North America was absent.

Mountain building took place in Western North America and Europe.

Both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in the American Great Plains and in Argentina.

Miocene Flora

Grasses begin to spread, and along with them grazing herbivores develop.

Miocene Fauna

Both marine and continental fauna were fairly modern. Only in isolated South America and Australia did widely divergent fauna exist.

Mammals

Recognizable wolves, horses, beaver, deer, camels, whales etc. existed in the Miocene.

Birds

Recognizable crows, ducks, and owls appear in the Miocene.

Miocene Oceans

The oceans continue cooling, and brown algae plants, called kelp, proliferate, supporting new species of sea life, including otters, fish and other invertebrates.

Desmostylus Hesperus

The Desmostylia are an extinct group of marine mammals. They are both strange and enigmatic creatures known only from deposits of the Late Oligocene and the Miocene.

Fossils assigned to four genera have been found in Japan and along the west coast of Mexico and the United States, to as far north as Washington. Above you can see the upper portion of a Desmostylus skull, with the forward-projecting teeth to the left.

Fossils of this creature were first described in 1888 by Othniel Marsh, from marine deposits collected in Alameda County, California. The fossils were considered to represent Sirenians, and subsequent fossils found in Japan

were interpreted as possibly being primitive Proboscideans (elephants) or Sirenians (sea-cows), though not without significant differences from either group.

Desmostylians are noted for having a number of bizarre and unique physical features, such as the tooth shown at right. (Click on the image to see a view of several teeth in a jaw.) The teeth and the pattern of wear in their enamel are unlike that observed in any modern mammal, and so no one is yet certain just what these short-tusked, shovel-jawed animals ate. This problem is compounded by the changes in coastal marine floras of the Miocene as kelp forests developed. The best evidence suggests they were herbivores, but anything beyond that is a guess.

Analogies have been made between the structure of desmostylians and the hippopotamus, though their lifestyle may have been more like that of the sealion. Fossil skeletons indicate that, unlike sea-cows, desmotylians were capable of moving around on land, but it is believed they did so primarily for rest or to mate.

The problematic morphology and relatively short stratigraphic range of these animals has caused them to be placed in a separate mammalian order. Their closest relatives include the elephants and sea-cows.

The first member of this family was Protoceras, which lived in the hills and mountains of western South Dakota during the late Oligocene, just a few million years before the day we are visiting at Agate.

Paleontologists have found battered scraps of its skeletons in the White River Badlands where perhaps they were washed by heavy spring rains running off the hills to the west. Protoceras had six bony bumps on its head that presumably bore short horns; one pair was over the nose, another was over the eyes, and a third was near the back of the skull.

Probably it was the direct ancestor of Syndyoceras. If Syndyoceras fails somehow to qualify as grotesque, let's jump a few million years into the "future" and look at his early Pliocene descendant, Synthetoceras ("combined horn"). Here was an animal on a par with unicorns and cyclopses. Like Syndyoceras he had two tall horns at the back of his head; but something had happened to the curved ones on his nose.

They had, during several million years of evolution, grown together into a single shaft and then spread out again to the sides and up. What a pity there were no little boys then, for here we have the world's first and only self-propelled slingshot! Tie a rubber band to the tips of his nose horns, fill your pocket with pebbles, and saddle up.

Procoptodon was one of seventeen species in three genera in the Sthenurine family, all of which are extinct. Sthenurines inhabited open woodlands in central Northern Australia as the tropical rainforests were beginning to retreat. All Sthenurines had an extremely developed,

almost hoof-like, fourth toe on the hindlimbs, with other toes vestigial.

Additionally, elastic ligaments between the toe bones gave this group improved spring and speed compared to modern kangaroos. Sthenurine forelimbs were long with two extra long fingers and claws compared with the relatively small, stiff arms of modern macropods. These may have been used for pulling branches nearer for eating and for quadrupedal movement for short distances.

Having attended Exeter College, Oxford ending in 1816, Lyell encountered geology as a serious profession under the wing of William Buckland. Upon graduation he took a professional detour into the law, but dabbled in geology. His first paper, "On a Recent Formation of Freshwater

Limestone in Forfarshire", was presented in 1822. By 1827 he had abandoned the law and embarked on a long geological career that would result in the widespread acceptan -(hi)-ce of the ideas proposed by James Hutton a few decades before.

His most important specific work was in the field of stratigraphy. In 1828, he travelled to the south of France and to Italy, where he realised that the recent strata could be categorised according to the number and proportion of marine shells encased within. Based on this he proposed dividing the Tertiary period into three parts, which he named the Pliocene, Miocene, and Eocene.

From 1830 to 1833 his multi-volume Principles of Geology was published. The work's subtitle was "An Attempt to Explain the Former Changes of the Earth's Surface by Reference to Causes now in Operation", and this explains Lyell's impact on science. He was, along with the earlier John Playfair, the major advocate of the then-controversial idea of uniformitarianism, that the earth was shaped entirely by slow-moving forces acting over a very long period of time.

This was in contrast to catastrophism, a geologic idea that went hand-in-hand with age of the earth as implied by biblical chronology. In various revised editions (twelve in all, through 1872), Principles of Geology was the most influential geological work in the middle of the 19th century, and did much to put geology on a modern footing. For his efforts he was knighted in 1848, then made a baronet in 1864.

During the 1840s, he travelled to the United States and Canada, which resulted in his writing two popular travel-and-geology books: 1845's Travels in North America and A Second Visit to the United States (from 1849).

Charles Darwin was a close personal friend, and Lyell was one of the first prominent scientists to support The Origin of Species — though he never fully accepted natural selection as the driving engine behind evolution.

In fact, Lyell was instrumental in arranging the peaceful co-publication of the theory of natural selection by Darwin and Alfred Russel Wallace in 1858, after each discovered it independently. Lyell's own The Geological Evidence of the Antiquity of Man followed a few years later in 1863.

Sometimes it has been classified as a member of Eucynodonts (a mammal-like reptile group), and sometimes it has been classified as a primitive mammal in the subclass of Prototheria, order Doconta (extinct) or Tricodonta. What makes Morganucodon special is that some of its upper jaw resembles that of reptiles.

Inscisives are not placed in the preamaxillaria (like mammals), but in the maxillaria (like some specialized Therapsida). The lower jaw has only reptile elements.

More research is needed to find out more about this species.

This lion-sized cat was the last of the family Nimravidae (false-saber-tooth cats) and lived during the late Miocene, about 15-7 million years ago. Fossils have been found in North America, Turkey, and Spain. Classification: Class Mammalia (mammals), Order Carnivora, Superfamily Feloidea (cats, mongooses), Family Nimravidae (false-saber-tooth cats, early cats), Genus Barbourofelis.

A big male stood about 4 to 4.5 meters tall at the shoulders. Its range covered parts of Asia, Africa, and Europe. Adrienne Mayor, in The First Fossil Hunters: Paleontology In Greek and Roman Times, has suggested that Deinothere fossils found in Greece helped generate myths of archaic giant beings.

A tooth of a deinothere found on the island of Crete, in shallow marine sediments of the Miocene (see link) raises questions: was Crete connected to the mainland during that time, or did Deinotheres share the often underrated swimming abilities of modern elephants?

It largely resembled modern elephants, except that its trunk was not as long, and it had downward curving tusks attached to the lower jaw.

The way Deinotherium used its curious tusks has been much debated. It may have rooted in soil for underground plant parts like roots and tubers, pulled down branches to snap them and reach leaves, or stripped soft bark from tree trunks. Deinotherium fossils have been uncovered at several of the African sites where remains of hominids, prehistoric relatives of modern human beings, have also been found.

Deinotherium is the type genus of the group of Proboscidea called Deinotheres. The large group to which elephants belong formerly contained several other related groups: besides the deinotheres there were the gomphotheres (some of which had shovel-like lower front teeth), and the mastodonts. Only elephants survive today.

The Oligocene epoch is a geologic period of time that extends from about 34 million to 23 million years before the present. As with other older geologic periods, the rock beds that define the period are well identified, but the exact dates of the start and end of the period are slightly uncertain. The name Oligocene refers to the sparsity of additional modern mammalian faunas after a burst of evolution during the Eocene.

The Oligocene follows the Eocene epoch and is followed by the Miocene epoch. The Oligocene is the third and final epoch of the Palaeogene period.

The start of the Oligocene is marked by a major extinction

event that may be related to the impact of large extraterrestrial object in Siberia and/or near Chesapeake Bay.

The Oligocene-Miocene boundary is not set at an easily identified worldwide event but rather at regional boundaries between the warmer Oligocene and the relatively cooler Miocene.

Oligocene Subdivisions

Oligocene faunal stages from youngest to oldest are:

Chattian (28.4 ± 0.1 – 23.03 MYA)

Rupelian (33.9 ± 0.1 – 28.4 ± 0.1 MYA)

Oligocene Climate

Climates remained warm, although the slow global cooling that eventualty led to the Pleistocene glaciations started around the end of the epoch.

Oligocene Paleogeography

During this period, the continents continued to drift toward their present positions.

Mountain building in western North America continued, and the Alps started to rise in Europe as the African plate continued to push north into the Eurasian plate. A brief marine incursion marks the early Oligocene in Europe. Oligocene marine exposures are rare in North America. There appears to have been a land bridge in the early Oligocene between North America and Europe as the faunas of the two regions are very similar.

Oligocene Flora

Angiosperms continued their expansion throughout the world; tropical and sub-tropical forests were replaced by temperate deciduous woodlands. Grasses expanded from the water-bank habitat in the Eocene, and moved out into open tracts.

In North America, subtropical species dominated with cashews and lychee trees present, and temperate trees such as roses, beech and pine common. The legumes of the pea and bean family spread, and sedges, bulrushes and ferns continued their ascent.

Oligocene Fauna

Important Oligocene land faunas are found on all continents except Australia. Marine faunas became fairly modern, as did terrestrial vertebrate faunas in the northern continents. This was probably more as a result of older forms dying out than as a result of more modern forms evolving.

South America was apparently isolated from the other continents and evolved a quite distinct fauna during the Oligocene.

Oligocene Oceans

Oceans continued to cool, particularly around Antarctica.

Indricotherium

Baluchitherium (also called Indricotherium; full name: Baluchitherium grangeri) was a gigantic hornless rhinoceros. It lived in Asia during the late Oligocene and early Miocene epoch of the Tertiary Period, 20-30 million years ago and went extinct 10 million years ago. Its name means 'The Beast from Baluchistan.' Baluchitherium is believed to have been the largest land mammal ever to have lived. It stood 5.5 m (18 ft) high at the shoulders and was 9 m (30 ft) long.

Its skull was about 2 m/6.6 ft in length, its limbs were long and massive, and it weighed about 20 tons. It was a herbivore that stripped leaves from trees with its down-pointing tusklike upper teeth that occluded forward-pointing lower teeth. Fossilized bones of baluchitherium have been found in central Asia. They may have been limited to Asia, for their fossils have not been found elsewhere.

Arsinoitherium was very selective in the types of fruit and leaves it ate. Its size meant it had to eat a lot of food - it probably spent much of its day chewing on something.

Arsinoitherium lived in small groups and would have been in the water most of the time. It couldn't straighten its legs, suggesting they were better for wading and swimming than for walking. Its large size kept it safe from most predators, although creodonts might tackle a young Arsinoitherium.

Pseudaelurus was approximately the size of a cougar by the time it died out.

This beast has poor eyesight, but makes up for this with keen hearing and smell. If raised from a calf, a baluchiterium can be trained as a beast of burden.

This immensely large, strong creature can carry up to 4 tons of weight as a pack animal. The baluchitherium is a very defensive animal, and attacks any animal that is nearby. This beast tries to charge and trample foes with its front feet.

Epoch: Oligocene

Geographical Zone: South America

weight: 30 kilos

Height: 0.5 meters

Carnivorous.

Boryhyaena it was a carnivorous marsupial that lived in South America it makes approximately Million 25 years ago behind, during the Oligoceno. It was possessing a bit more than 1 meter of length and was a species not adapted well to compete with other mammals, which between other factors they will take it to the extinction.

The Eocene epoch (56-34 MYA) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. The Eocene spans the time from the end of the Paleocene epoch to the beginning of the Oligocene epoch. The start of the Eocene is marked by the emergence of the first modern mammals.

The end is set at a major extinction event that may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. Still, as with other other geologic periods, the strata that define the start and end of the epoch are well identified, but their exact dates are slightly uncertain.

The name Eocene refers to the "dawn" of modern ('new')

mammalian fauna that appeared during the epoch.

Eocene subdivisions

The Eocene is usually broken into lower and upper subdivisions. The Faunal stages from youngest to oldest are:

Priabonian (37.2 ± 0.1 – 33.9 ± 0.1 MYA)

Bartonian (40.4 ± 0.2 – 37.2 ± 0.1 MYA)

Lutetian (48.6 ± 0.2 – 40.4 ± 0.2 MYA)

Ypresian (55.8 ± 0.2 – 48.6 ± 0.2 MYA)

Eocene climate

Marking the start of the Eocene, the planet heated up in one of the most rapid (in geologic terms) and extreme global warming events recorded in geologic history, called the Paleocene-Eocene Thermal Maximum or Initial Eocene Thermal Maximum (PETM or IETM). This was an episode of rapid and intense warming (up to 7°C at high latitudes) that lasted less than 100,000 years The Thermal Maximum provoked a sharp extinction event that distinguishes Eocene fauna from the ecosystems of the Paleocene.

Climates remained warm through the rest of the Eocene, although slow global cooling, which eventually led to the Pleistocene glaciations, started around the end of epoch as ocean currents around Antarctica cooled.

Eocene paleogeography

During the Eocene, the continents continued to drift toward their present positions.

At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents mixed with colder Antarctic waters, distributing the heat around the world and keeping global temperatures high.

But when Australia split from the southern continent around 45 mya, the warm equatorial currents were deflected away from Antarctica, and an isolated cold water channel developed between the two continents. The Antarctic region cooled down, and the ocean surrounding Antarctica began to freeze, sending cold water and icefloes north, reinforcing the cooling.

The northern supercontinent of Laurasia began to break up, as Europe, Greenland and North America drifted apart.

In western North America, mountain building started in the Eocene, and huge lakes formed in the high flat basins among uplifts.

Europe saw the Tethys Sea finally vanish, while the uplift of the Alps isolated its final remnant, the Mediterranean, and created another shallow sea with island archipelagos to the north.

Though the North Atlantic was opening, a land connection appears to have remained between North America and Europe as the faunas of the two regions are very similar.

India continued its journey away from Africa, and began its collision with Asia, folding the Himalayas into existence.

Eocene flora

At the beginning of the Eocene, the high temperatures and warm oceans created a moist, balmy environment, with spreading throughout the earth from pole to pole.

Cooling began mid-period, and by the end of the Eocene continental interiors had begun to dry out, with forests thinning out considerably in some areas. The newly-evolved grasses were still confined to river banks and lake edges, and had not yet expanded into plains and savannas.

The cooling also brought seasonal changes. Deciduous trees, better able to cope with large temperature changes, began to overtake evergreen tropical species. By the end of the period, deciduous forests covered large parts of the northern continents, including North America, Eurasia and the Arctic, and rainforests held on only in equatorial South America, Africa, India and Australia.

Antarctica, which began the Eocene fringed with a sub-tropical rainforest, became much colder as the period progressed; the heat-loving tropical flora was wiped out, and by the beginning of the Oligocene the continent hosted deciduous forests and vast stretches of tundra.

Eocene fauna

Mesonyx, a carnivore ungulateThe oldest known fossils of most of the modern mammal orders appear within a brief period during the early Eocene. At the beginning of the Eocene, several new mammal groups arrived in North America. These modern mammals, like artiodactyls, perissodactyls and primates, had features like long, thin legs, feet and hands capable of grasping, as well as differentiated teeth adapted for chewing. Dwarf forms reigned.

All the members of the new mammal orders were small, under 10 kg; based on comparisons of tooth size, Eocene mammals were only 60 per cent of the size of the primitive Paleocene mammals that had preceded them. They were also smaller than the mammals that followed them. It is assumed that the hot Eocene temperatures favored smaller animals that were better able to manage heat.

Both groups of modern ungulates (hoofed animals) became prevalent due to a major radiation between Europe and North America; along with carnivourous ungulates like Mesonyx. Early forms of many other modern mammalian orders appeared, including bats, proboscidians, primates, rodents and marsupials. Older primitive forms of mammals declined in variety and importance. Important Eocene land fauna fossil remains have been found in western North America, Europe, Patagonia, Egypt and South-East Asia. Marine fauna are best known from South Asia and the southeast United States.

During the Eocene plants and marine faunas became quite modern. Many modern bird orders first appear in the Eocene.

Eocene oceans

The Eocene oceans were warm and teeming with fish and other sea life. The first Carcharinid sharks appeared, as did early marine mammals, including Basilosaurus, an early species of whale that is thought to be descended from land animals, the hoofed predators called mesonychids, of which Mesonyx was a member.

Adapis

Taxonomy:

suborder: Strepshirini

superfamily: Adapoidea

family: Adapidae

subfamily: Adapinae

Morphology:

Adapis parisiensis has a dental formula of 2:1:4:3 on both the upper and lower jaw (Fleagle, 1988). The upper central incisors are broad and spatulate and there is a gap between their bases (Fleagle, 1988). No sexual dimorphism occurred in the size of the upper canines (Fleagle, 1988). The lower incisors and canines form a single cutting edge suggesting a possible exaptation for the tooth comb seen in extant lemurs (Fleagle, 1988). The incisors also have fine parallel striations that are also found in extant lemurs, suggesting their use in grooming (Fleagle, 1988).

Although Martin (1990) suggest that this species did not have a toothcomb, but the lower dentition shows an adaptation for dietary reasons. This species had molars and premolars that were long, narrow, and had high shearing crests (Fleagle, 1988). The upper molars of this species have a true hypocone (Martin, 1990). The symphysis of the lower jaw was fused which is a character lacking in extant strepsirrhines (Martin, 1990). The skull of this species is low and broad with a small braincase and flaring zygomatic arches (Fleagle, 1988).

Evidence shows that the brain of this species had a true Sylvian sulcus (Martin, 1990). This true Sylvian sulcus may be connected with the expansion of the visual cortex (Martin, 1990). The orbits of this species are small relative to other adapids suggesting that this was a diurnal species (Fleagle, 1988). This species had a relatively large temporal fossa (Fleagle, 1988). The auditory region has an inflated bulla with a free tympanic (Fleagle, 1988).

A canal exists for the stapedial artery and a groove for a promontory artery (Fleagle, 1988). This species had an average body mass of around 1.3 kilograms (Fleagle, 1988).

Range:

Adapis parisiensis was found in Europe and occurred during the late Eocene to the early Oligocene, going extinct during the major European faunal turnover called the Grand Coupure (Fleagle, 1988).

Diet:

Based on dental morphology, the high shearing crests of the molars, this species most likely had a folivorous diet (Fleagle, 1988).

Locomotion:

Based upon the limb bones this species most likely had a slow climbing arboreal quadrupedalism type of locomotion much like that of the extant Nycticebus coucang and Perodicticus potto (Fleagle, 1988).

Uintatherium was an ancient, distant cousin of horses, elephants and whales.

Vital Statistics

Name: Uintatherium

Length: 10-15 feet

Weight: 5,000-6,000 pounds

Time: Late Eocene

Place: Asia, North America

Diet: plant-eater (herbivore)

The canines are somewhat elongated, and were followed by a short gap in each jaw, and the cheek-teeth were adapted for succulent food. The length of the body reached about six feet in some cases. In the middle Eocene formations of

North America occurs the more specialized Hintatherium (or Dinoceras), typifying the family Uintatheriidae, which also contains species sometimes separated as Tinoceras. Uintatheres were huge creatures with long narrow skulls, of which the elongated facial portion carried three pairs of bony horn-cores, probably covered with short horns in life, the hind-pair

being much the largest. The dental formula is i. 0/3, c. 1/1, p. 3/3·4, m. 3/3; the upper canines being long sabre-like weapons, protected by a descending flange on each side of the lower front jaw.

In the basal Eocene of North America, the Amblypoda were represented by extremely primitive, five-toed, small ungulates such as Periptychus and Pantolambda, each of these typifying a family. The full typical series of 44 teeth was developed in each, but whereas in the Periptychidae the upper molars were bunodont and tritubercular, in the Pantolambdidae they have assumed a selenodont structure. Creodont characters are displayed in the skeleton.

Archaeocete skeletons complete enough to be informative about locomotion are rare (principally Rodhocetus and Dorudon), and these deserve to be studied in comparison to the full spectrum of semiaquatic mammals. A principal components analysis of 14 trunk and limb measurements for 50 species of living semiaquatic mammals reduces the observed variation to

three informative axes. The first principal axis (PC-I) represents overall size (water mice and shrews have the lowest scores on this axis and the hippopotamus has the highest); the second axis (PC-II) represents a spectrum of aquatic adaptation (seals have the lowest scores and tapirs have the highest); and the third principal axis (PC-III) represents a spectrum ranging from hindlimb- to forelimb-dominated locomotion (sea otters have the lowest scores and the platypus the highest).

Dorudon fits poorly into a morphospace defined solely by living semiaquatic mammals; thus a second 53-species set was analyzed, adding an anthracothere to represent an artiodactyl ancestral morphology and two species of archaeocetes to represent successive stages of early whale evolution. This addition has little effect on the first two principal axes but changes the third substantially.

PC-III now represents a contrast of lumbus- (and presumably tail-) dominated versus hindlimb-dominated locomotion (Dorudon has the lowest score and Rodhocetus the highest, whereas the otter shrew has the lowest score among living mammals and the desman the highest). Mammals that are more aquatic have a shorter ilium and femur combined with longer manual and pedal phalanges, whereas the reverse is true for more terrestrial taxa.

Lumbus- and tail-dominated swimmers tend to have a longer lumbus combined with shorter pedal elements, whereas the reverse is true for hindlimb-dominated swimmers. Trunk and limb proportions of early middle Eocene Rodhocetus are most similar to those of the living, highly aquatic, foot-powered desmans. Trunk and limb proportions of late middle Eocene Dorudon indicate that it was a lumbus-and-tail-powered swimmer specialized in the direction of modern whales.

Thus it appears that the land-to-sea transition in whale evolution involved at least two distinct phases of locomotor specialization: (1) hindlimb domination for drag-based pelvic paddling in protocetids (Rodhocetus), with tail elongation for stability, followed by (2) lumbus domination for lift-based caudal undulation and oscillation in basilosaurids (Dorudon). Rates of evolution in both phases of this change of adaptive zone are about an order of magnitude higher than background rates for the timescale involved.

The Paleocene epoch (65-56 MYA) ("early dawn of the recent") is the first geologic epoch of the Palaeogene period in the modern Cenozoic era. As with most other older geologic periods, the strata that define the epoch's beginning and end are well identified, but the exact date of the end is uncertain.

The Paleocene epoch immediately followed the mass extinction event at the end of the Cretaceous, known as the K-T boundary (Cretaceous - Tertiary), which marks the demise of the dinosaurs. The die-off of the dinosaurs left

unfilled ecological niches worldwide, and the name "Paleocene" refers to the "old(er) – new" fauna that arose during the epoch, prior to the emergence of modern mammalian orders in the Eocene.

The K-T boundary that marks the separation between Cretaceous and Paleocene is visible in the geological record of much of the Earth by a discontinuity in the fossil fauna, with high Iridium levels. There is also fossil evidence of abrupt changes in flora and fauna. There is some evidence that a substantial but very short-lived climatic change may have occurred in the very early decades of the Paleocene. There are a number of theories about the cause of the K-T extinction event, with most evidence supporting the impact of a 10 km diameter asteroid near Yucatan, Mexico.

The end of the Paleocene (55.5/54.8 Ma) was marked by one of the most significant periods of global change during the Cenozoic, a sudden global change, the Paleocene-Eocene Thermal Maximum, which upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and on land, a major turnover in mammals.

Tertiary sub-era

Palaeogene period

Paleocene epoch Eocene epoch Oligocene epoch

Danian | Selandian |

Thanetian Ypresian | Lutetian |

Bartonian | Priabonian Rupelian | Chattian

Paleocene subdivisions

The Paleocene is usually broken into lower and upper subdivisions. The faunal stages from youngest to oldest are:

Thanetian (58.7 ± 0.2 – 55.8 ± 0.2 MYA)

Selandian (61.7 ± 0.2 – 58.7 ± 0.2 MYA)

Danian (65.5 ± 0.3 – 61.7 ± 0.2 MYA)

Paleocene climate

Temperatures rose during the Paleocene, and the climate was warm and humid world-wide, with subtropical vegetation growing in Greenland and Patagonia. The poles were cool and temperate, North America, Europe, Australia and southern South America were warm and temperate; tropical climates characterized equatorial areas, and North and South of the Equator climates were hot and arid.

Paleocene paleogeography

During the Paleocene, the continents continued to drift toward their present positions. North America, Europe and Asia were still joined in a supercontinent, Laurasia, but Greenland and North American were beginning to separate.

The southern supercontinent Gondwanaland continued to split apart, with Africa, South America, Antarctica and Australia pulling away from each other. Africa was heading north towards Europe, and India began its migration to Asia that would lead to the huge tectonic collision and formation of the Himalayas.

South and North America were still separated by vast equatorial seas. The warm Tethys Ocean continued to dominate the globe.

The inland seas in North America (Western Interior Seaway) and Europe receded and eventually disappeared, making way for new land-based flora and fauna.

Paleocene flora

On land, modern plant species developed. Cacti and palm trees appeared. Paleocene and later plant fossils are generally attributed to modern genera or to closely related taxa.

The warm temperatures world-wide gave rise to thick tropical, sub-tropical and deciduous forest cover around the globe, with ice-free polar regions covered with pine trees, and deciduous forests in the north. Flowering plants (angiosperms), first seen in the Cretaceous, continued to develop and proliferate, and along with them coevolved the insects that fed on these plants and pollinated them.

Paleocene fauna

Mammals

Mammals had first appeared in the Triassic, and developed alongside the dinosaurs, exploiting ecological niches untouched by the larger and more famous Mesozoic animals: in the insect-rich forest underbrush, and high up in the trees. These smaller mammals (as well as birds, reptiles, amphibians, and insects) survived the mass extinction at the end of the Cretaceous, which wiped out the dinosaurs, and mammals diversified and spread throughout the world.

While early mammals were small nocturnal animals with herbivorous and insectivorous diets, the demise of the dinosaurs and the beginning of the Paleocene saw mammals growing bigger, more ferocious, and finally becoming the dominant predators and spreading throughout the world. Ten million years after the death of the dinosaurs, the world was filled with rodent-like mammals, medium sized mammals scavenging in forests, and large herbivorous and carnivorous mammals hunting other mammals, birds, and reptiles.

Paleocene mammals did not yet have specialized teeth or limbs, and are considered primitive, or archaic. It was not until the Eocene, 55 MYA, that true modern mammals developed.

Fossil evidence from the Paleocene is scarce, and there is relatively little known about mammals of the time. Because of their small size, early mammal bones are not well-preserved in the fossil record, and most of what we know comes from fossil teeth (a much tougher substance), and only a few skeletons.

Mammals of the Paleocene include:

Monotremes: three species of monotremes have survived to modern times: the duck-billed platypus, and two species of Echidnas. Monotrematum sudamericanum lived during the Paleocene.

Marsupials: modern kangaroos are marsupials, characterized by giving birth to embryonic babies, who crawl into the mother's pouch and suckle until they are developed. The Bolivian Pucadelphys andinus is a Paleocene example.

Multituberculates: the only extinct mammalian family, this rodent-like grouping includes the Paleocene Ptilodus.

Placentals: this grouping of mammals became the most diverse and the most successful. Members include hoofed ungulates, primates and carnivores, such as the Paleocene mesonychid.

Reptiles

Due to the climatic conditions of the Paleocene, reptiles were more cosmopolitian than at present. Among the sub-tropical reptiles found in North America during this epoch are champsosaurs (aquatic reptiles that resemble modern gavials), crocodylians, soft-shelled turtles, palaeophid snakes, varanid lizards, and Protochelydra zangerli (similar to modern snapping turtles).

Examples of champsosaurs of the Paleocene include Champsosaurus gigas, the largest champsosaur ever discovered. This creature was unusual among Paleocene reptiles in that C. gigas begame larger than its known Mesozoic ancestors: C. gigas is more than twice the length of the largest Cretaceous specimens (3m vs. 1.5m). Reptiles as a whole decreased in size after the K-T event. Champsosaurs declined towards the end of the Paleocene and became extinct at the end of the Eocene.

Examples of Paleocene crocodylians are the early eusuchian crocodile Leidyosuchus formidabilis, the apex predator and the largest animal of the Wannagan Creek fauna, and the alligator Wannaganosuchus.

Birds

Birds began to diversify during the epoch, occupying new niches. Most modern bird types had appeared by mid-Cenozoic, including perching birds, cranes, hawks, pelicans, herons, owls, ducks, pigeons, loons, and woodpeckers.

Large carnivorous flightless birds (also called Terror Birds) have been found in late Paleocene fossils, including the fearsome Gastornis in Europe.

Early owl types such as Ogygoptynx and Berruornis appear in the late Paleocene in the U.S. and France respectively.

Paleocene oceans

Warm seas circulated throughout the world, including the poles. The warm oceans gave rise to abundant marine life, including coral reefs. With the demise of marine reptiles at the end of the Cretaceous, sharks became the top predators. The end of the Cretaceous also saw extinctions of the ammonites, and many species of foraminifera.

Marine faunas also came to resemble modern faunas, with only the marine mammals and the Charcharinid sharks missing.

Nunmulites

Nummulites are virtually extinct, giant marine protists that reached up to 160 mm diameter during the warmest climatic phase of the Cenozoic. Until now, their life span and paleoenvironmental tolerance have remained enigmatic.

Pioneering the use of high-resolution drilling techniques in Nummulites, we show that both N. laevigatus and coeval bivalve Venericardia planicosta from the Lutetian of Hampshire, United Kingdom (ca. 50–42.5 Ma), underwent strong, annual alternations in carbon and oxygen isotopes, possibly reflecting tolerance of broad environmental variation. Our data demonstrate a life span of at least 5 yr for N. laevigatus, and we estimate that the largest species may have lived for more than 100 yr.

One Pantodont was called Pantolambda. Although it resembled a cat in its overall appearance, the creature had hoof-like clawed feet and ate plants.Pantolambda was about the size of a sheep. Another Pantodont was Barylambda. It was about 6 and a half feet long.

The Paleocene (65-54 million years ago) was the first period of the Age of Mammals. With the dinosaurs gone the mammals could now roam freely and many mutated and became larger. One family of Paleocene mammals were the Pantodonts. These animals were herbivores and lived in Asia and both of the American continents. One Pantodont was called Pantolambda.

Although it resembled a cat in its overall appearance, the creature had hoof-like clawed feet and ate plants.Pantolambda was about the size of a sheep. Another Pantodont was Barylambda. It was about 6 and a half feet long. Pantodonts were successful for a long time. They finally died out in the Oligocene period (38-26 million years ago).

Besides its occurrence in clearly early Paleocene sediments, remains of this genus are also found together

with the teeth of dinosaurs. Therefore it was originally thought that Protungulatum (and some other types of mammals) appeared in the latest Cretaceous and co-existed with the last dinosaurs and with typically Cretaceous mammals in the so-called "Bugcreekian" faunas.

In this scenario, early ungulates like Protungulatum would have been in competition with the herbivorous dinosaurs and could have contributed to the demise of these reptiles. However, a more recent interpretation is that the "Bugcreekian" assemblages are a mixture of early Paleocene and latest Cretaceous fossils, the latter having been eroded by rivers from older sediments and redeposited together with fresh animal remains in the early Paleocene.

The issue is not finally resolved, but this new interpretation fits to the idea that mammals filled the vacant ecological niches after a catastrophic extinction of the dinosaurs, which may have been caused by the impact of a large meteorite. Whatever the precise age of the fossils, the status of Protungulatum as prototype for the later ungulates has not been challenged since its first description in 1965. Although still quite primitive, the dentition of Protungulatum foreshadows the typical trends observed in ungulates: Its teeth are low and have increased potential for crushing and grinding food, which probably allowed the animal to feed on soft plants, fruits and still some insects.

Only few bones are known for these earliest condylarths beyond their jaws and dentition, so a lot remains to be learnt about their biology. Yet it is a big progress that potential ancestors of Protungulatum have recently been identified in the late Cretaceous of Uzbekistan. These small placental animals, called zhelestids, are not strictly classified as ungulates, but their teeth may show us a first stage in the evolution of an ungulate-like dentition.

Protungulatum is traditionally regarded as a member of the Arctocyonidae, a family that was diverse and abundant in the Paleocene of North America and Europe. The arctocyonids are the least herbivorous group of condylarths. In fact their skulls look superficially like those of carnivores, with large canines and relatively sharp teeth, but arctocyonids had no specialized teeth for slicing meat and were probably omnivores.

The limbs of arctocyonids were relatively short and showed none of the specializations that we typically associate with ungulates, like reduction of the side digits, fusion of bones or the possession of hoofs. Many arctocyonids are only known from their teeth, which show much individual variation, so the taxonomy of arctocyonid genera and species is highly unstable.

The Cro-Magnons form the earliest known European examples of Homo sapiens sapiens, the subspecies to which modern humans belong. The term falls outside the usual naming conventions for early man and is used in a general sense to describe the oldest modern people in Europe.

They lived from about 35,000 to 10,000 years ago in the

Upper Paleolithic period of the Pleistocene epoch. For all intents and purposes these people were anatomically modern, only differing from their modern day descendants in Europe by their slightly more robust physiology and brains which were about 4 percent larger than that of modern man.

The Cro-Magnons could be descended from any number of subspecies of Homo sapiens that emerged from Africa approximately 100,000 years ago, such as Homo sapiens idaltu.

The geologist Louis Lartet discovered the first five skeletons in March 1868 in the Cro-Magnon rock shelter at Les Eyzies, Dordogne, France. The definitive specimen from this find bears the name 'Cro Magnon I'. The skeletons showed the same high forehead, upright posture and slender (gracile) skeleton as modern humans. Other specimens have since come to light in other parts of Europe and in the Middle East. The European individuals probably arrived from north Africa and the Middle East.

Surviving Cro-Magnon artifacts include huts, paintings, carvings and antler-tipped spears. The remains of tools suggest that they knew how to make woven clothing. They had huts, constructed of rocks, clay, bones, branches, and animal hide/fur. These early humans used manganese and iron oxides to paint pictures and it is believed that they created the first calendar around 32,000 B.C. The flint tools found in association with the remains at Cro-Magnon have associations with the Aurignacian culture that Lartet had identified a few years before he found the skeletons.

Art of the Cromagnon Man:

It includes The Paleolithic Venus , colective and individual hunting scenes with spear, deer and mammoths.

Their brains were roughly 10 percent larger than those of modern humans. On average, Neanderthals stood about 1.65m tall (just under 5' 6") and were very muscular, comparable to modern weight-lifters.

Their characteristic style of stone tools is called the Mousterian Culture, after a prominent archaeological site where the tools were first found.

Discovery

The first Neanderthal fossils were found in August, 1856, three years before Charles Darwin's Origin of Species was published. The fossils were found in a limestone quarry near Düsseldorf in the Neanderthal, Germany.

The type specimen, dubbed Neanderthal 1, consisted of a skull cap. Other material found were two femora, the three right arm bones, two of the left arm bones, part of the left ilium, and fragments of a scapula and ribs. They were originally thought to be bear remains by the workers who recovered it. The workers gave the material to amateur naturalist Johann Karl Fuhlrott. Fuhlrott turned the fossils over to anatomist Hermann Schaafhausen and in 1857 the discovery was jointly announced.

That discovery is now considered the beginning of paleoanthropology. These and other discoveries ultimately led to the idea that these remains were from ancient Europeans who had played an important role in modern human origins. Over 400 Neanderthals have been found since.

Name and classification

The term "Neanderthal Man" was coined in 1863 by Irish anatomist William King. Neanderthal is now spelled two ways: The spelling of the German word Thal, meaning "valley", was changed to Tal in the early 20th century, but the former spelling is retained in English and in scientific names, while the modern spelling is used in German.

For many years, there was a vigorous professional debate about whether Neanderthals should be classified as Homo neanderthalensis or Homo sapiens neanderthalensis. The latter places Neanderthals as a subspecies of Homo sapiens; however, recent evidence from mitochondrial DNA studies indicates that Neanderthals were not a subspecies of Homo sapiens.

It is generally accepted that both Neanderthals and Homo sapiens evolved from earlier "archaic" Homo sapiens, but the classification of Neanderthals depends on when in the timeline these modern humans are considered a separate species from the "archaic" forms. This complication is introduced because the "archaic" forms are a chronospecies.

Physical traits

Compared to modern humans, Neanderthals were larger in size and had

different cranial features. Much of their size is understood to be an adaptation to the cold climate of Europe during the Pleistocene epoch. The following is a list of physical traits that distinguish Neanderthals from modern humans; however, not all of them can be used to distinguish Neanderthals from other extinct populations. Also, many of these traits can occasionally occur in modern humans. Nothing is known about the skin color, the hair, or the shape of soft parts such as eyes, ears, and lips of Neanderthals.

Cranial

Suprainiac fossa, a groove above the inion

Occipital bun, a protuberance of the occipital bone that looks like a hair knot

Projecting mid-face

Globe-shaped skull (from rear)

Low, flat, elongated skull

Supraorbital torus, a browridge

1200-1700 cm³ skull capacity (slightly greater than that of modern humans)

No chin

Crest on the mastoid process behind the ear opening

No groove on canine teeth

A space behind the last molars

A broad, projecting nose

Bony projections on the side of the nose opening

Different shape of the bony labyrinth in the ear

Post-Cranial

Considerably more muscular

Large round finger tips

Barrel-shaped rib cage

Different shape of the pelvis

Large kneecaps

Long collar bones

Short, bowed shoulder blades

Thick, bowed shaft of the thigh bones

Short shinbones and calf bones

Language

The theory that Neanderthals lacked complex language was widespread until 1983, when a Neanderthal hyoid bone was found at the Kebara Cave in Israel. The bone that was found is virtually identical to that of modern humans. The hyoid is a small bone that holds the root of the tongue in place, and its presence seems to imply some ability to speak.

Many people believe that even without the hyoid bone evidence, it is obvious that tools as advanced as those of the Mousterian Era, attributed to Neanderthals, could not have been developed without cognitive skills encompassing some form of spoken language.

A recent study conducted on the Neanderthal hyoid found that due to the physical characteristics of Neanderthals and the fact that their Larynx would have been stouter than that of modern man, the average note emitted by Neanderthals would have been high pitched and sharper than that of modern man.

The base of the Neanderthal tongue was positioned higher in the throat, crowding the mouth somewhat. As a result, Neanderthal speech would have been slow-paced and nasalized.

Tools

Neanderthal (Middle Paleolithic) archeological sites show both a smaller and a less flexible toolkit than in the Upper Paleolithic sites, occupied by modern humans that replaced them.

There is little evidence that Neanderthals used antlers, shell, or other bone materials to make tools: their bone industry was at most incipient and crude. However, there is good evidence that they routinely constructed a variety of stone implements. The Neanderthal (Mousterian) tool case consisted of sophisticated stone-flakes, task-specific hand axes, and spears. Many of these tools were very sharp.

Also, while they had weapons, they were not used as projectile weapons. They had spears in the sense of a long wooden shaft with an arrow head firmly attached to it, but spears were first used as projectiles by Homo sapiens.

Although much has been made of the Neanderthal's burial of their dead, their burials were less elaborate than those of anatomically modern humans. The interpretation of the Shandiar IV burials as including flowers, and therefore being a form of ritual burial (Ralph Solecki 1975), has been questioned (Sommer 1999). In some cases Neanderthal burials include grave goods such as bison and aurochs bones, tools, and the pigment ochre.

Neanderthals performed a sophisticated set of tasks normally associated with humans alone. For example, they constructed complex shelters, controlled fire, and skinned animals. Particularly intriguing is a hollowed-out bear femur with four holes in the diatonic scale deliberately bored into it. This flute was found in western Slovenia in 1995 near a Mousterian Era fireplace used by Neanderthals, but its significance is still a matter of dispute. See: prehistoric music.

Popular culture

Popular literature has tended to greatly exaggerate the ape-like gait and related characteristics of the Neanderthals. It has been determined that some of the earliest specimens found in fact suffered from severe arthritis. The Neanderthals were fully bipedal and had a slightly larger average brain capacity than a typical modern human, though it's thought the brain structure was organised differently.

In popular idiom the word Neanderthal is sometimes used as an insult, to suggest that a person combines a deficiency of intelligence and an attachment to brute force. Counterbalancing this are sympathetic literary portrayals of Neanderthals, as in the novel The Inheritors by William Golding and Jean M. Auel's Earth's Children series, or the more serious treatment by palaeontologist Björn Kurtén, in several works including Dance of the Tiger.

Science fiction has depicted Neanderthals in several ways:

In The Ugly Little Boy by Isaac Asimov, a Neanderthal child is brought into the present via time travel.

Michael Crichton's 1976 novel Eaters of the Dead places a small Neanderthal population in Europe as the source of the battles recorded in Beowulf.

In the Riverworld series, Philip José Farmer introduces a prominent Neanderthal character named Kazz, who interacts with modern humans.

Robert Sawyer's Neanderthal Parallax trilogy portrays contact with an alternate world where Neanderthals, not Homo sapiens, became the dominant species. The first book in this series, Hominids, won the Hugo Award in 2003. (Sawyer's 1997 novel Frameshift used Neanderthal DNA as an element of a plot set in modern-day America.)