To the north of Mexican plateau, in the centre of North-American continent great plains are spread on hundreds kilometers. They are not so similar to plains of Holocene time: the climate began more damp, and in many places small lakes and the rivers were formed. Coasts of them richly grow by young growths trees, and on marges of these woods rich bushes grow. But the same time the most part of territory of plains is occupied by grasses, communities of different species of graminoids. Near reservoirs graminoids are replaced by rigid sedges, cane and reed mace. All these plants are united with one general feature - they easily maintain constant "clipping" by teeth of thousands herbivorous animals. Only among trees and bushes more delicate grassy plants can survive. But plains are the empire of graminoids. Each summer set of spikes, tassels and thick trusses of different grass species head to the sun and disseminate seeds. Perhaps, only such fantastic endurance and bent for of life what is at graminoids, supports viability and efficiency of plain grass community.
Herbivores of several species dominate in this landscape. On plains herds of strange, similar to horse and zebra, animals are grazing. These mammals are donkeyhorses, one of last solidungulates. Strange-looking animals similar to short-muzzled mules having striped legs, as if at zebra, live in herds under the rule of large stallion. Short muzzle of the donkeyhorse is the adaptation for rigid graminoids of plains grazing. The constitution of this animal is generated by life at plains: animals are very high, with strong hoofs and long legs. At them there are fine hearing and keen sight. Donkeyhorses are grazed in thickets of graminoids, from time to time tossing head and looking around. Animals are overcome by blood-sucking insects and flies, therefore they constantly sniff, snort as horses, and shake long ears with hairy brushes on ear tips. These animals do not approach close to bushes as feel, that among them predators can be hidden. But on open plain donkeyhorses feel like in safety: They can notice a large predator from afar just in time and skip away from it.
It seems, thickets of bushes in damp climate eventually will supersede photophilous grasses. But it do not happen, as on branches and leaves of bushes there are four-legged greenery eaters: massive peccasons and graceful deermaras. Peccason is a huge herbivore with large head and massive body, similar partly at the American bison. But as against the ruminant horned double, the peccason prefers to graze in damp meadows and bushes where it is fed with plants which swift-footed donkeyhorse not is: sedges and reed mace, and also moistureloving graminoids and bushes. Eating root shoots of bushes, peccason does not allow them to overgrow wide areas.
Near to massive peccasons other herbivores, deermaras graze also. These animals are not ungulates, but running rodents. They occupy an ecological niche of pronghorns, which had been numerous and diverse in North America, but had not survived in mass extinction at the edge of Holocene and Neocene. Deermaras eat leaves of bushes and young trees. Thus animals can rise on back legs, basing forelegs on tree trunk to reach the top branches. Besides the small size allows deermaras to be fed in places where large animals can not pass: between bushes. Delicate sappy non-graminoid grasses especially favorite by these rodents grow there.
On plains of America various species of herbivores are grazed, but they do not compete with each other because eat different species of plants. The unique place where interests of different animal species somehow coincide is the watering place. To the sparse lakes on plain numerous animal tracks lead. Here again is the best place for a predator to arrange an ambush. Feeling it, small inhabitants of plains try to keep near to large and strong ones.
The herd of peccasons under the leading of huge male with rich "beard" on the bottom jaw and neck slowly walks to the watering place. Among massive animals in clouds of dust raised by them some deermaras are seem. These long-legged rodents try to keep abreast from giants, but are compelled to evade blows of their strong hoofs. If the deermara casually stumbles it will be simply crushed in flat mass by weight of large peccary descendants. Some of brown giants chew grass broken on the move, others push away neighbours, making the way in the beginning of herd. Deermaras constantly make high jumps, evading giants indifferent to them. When the herd has approach to water, by the first order peccasons stand along the shore. Huge muzzles drop to water, legs are placed wide, and next animals rest each other by sides so densely, that even the dexterous deermara can not shove between them. When one of rodents comes sideways, it practically at once is banished by the two young peccasons, came a trace. Gradually got drunk animals depart from water and their place on the spot new ones take up. Deermaras hasty run across between massive peccasons, making whenever possible some drinks of water on an empty place.
But to be near to massive animals is nevertheless favourable: in grass the predator is hidden. The brown body slides among grass and bushes, trying to not give out the presence to massive peccasons. Softened spots and strips on his skin help to mask better from badly seeing herbivores. He is the representative of feline family, the balam, descendant of one of small Central-American cats. His body is extended, as if at the ferret, and strong hind paws are longer than forepaws. Balam is the expert in hunting for small prey, therefore a large peccason is not interesting for him though the cub strayed from herd can be easily caught by him and be eaten. But now cubs are protected by massive adult animals, and deermaras do not depart far from peccasons.
When the herd departs from water, deermaras are late at a watering place. It did not remain without attention of balam, and the large predator steals to several strayed animals. But when the distance to catch had remained literally two jumps, he was noticed: the treacherous rush had carried his smell up to peccasons. The herd at once raises alarm: adult females roar, calling up cubs. And the head of herd, the massive "bearded" male, leaves to the predator and shows its might. It loudly roars, throws by legs ground clods in the sides, shakes the head. The wool on its head rises on end. Balam indifferently looks at this demonstration and departs: he’ll never begin to attack the adult peccason male, but will manage to protect himself or to rescue himself on a tree if it will be required. The large cat looks back over a shoulder at roaring giant and hides in bushes.
And the herd of peccasons still long can not calm: females do not see the predator, and perceive any large creature which is coming nearer to cubs as threat. When the deermara carelessly approaches to bunched calves, one of peccason females attacks it, loudly breathing noisily. The attacked deermara makes a high jump that serves as a signal of danger to neighbours. And in one second all deermaras run away from herd of peccasons by high jumps.
Hunting near to reservoir can be very successful, but also sometimes it can be dangerous. On one of the next lakes had been once a part of channel of the large river, the female of balam and pair of her cubs search for a meal. These cats are very clever and use set of various sources of food. The female trains cubs to search for very nutritious and tasty meal - turtle eggs. She attentively examines and sniffs at the coast, hoping to find features of presence of the turtle had laid eggs. And in one place of sandy coast, under precipice protecting this place from herds of herbivores which are going down to the watering place, she finds something that had searched. By rumbling the female calls up kittens, gives them to sniff around sand, and starts to dig it by forepaws. Soon under sand layer some eggs in size with large chicken are found out. The balam female snaps one egg, takes a bite of it, and, holding by paw, licks the shell contents. Kittens try to repeat it, but an egg is too large for their mouths. Then the female tears a shell by canine and rumbling invites kittens to meal. Gradually the nest becomes empty.
The sated kittens game. One of them plays with the tail tip of mother having a rest on the coast, and another one tries to catch a blue dragonfly sat down on stick near water. He squats, being shrunk as a lump, and tries to overtake a prompt insect by clumsy jump. But the dragonfly safely flies out, and the kitten flops right in water. He flounders in water and desperately mews. Mother instantly jumps up and accurately takes from water wet shivering offspring. But small incident had drawn attention of another predator. The huge head covered with corneous shell, emerges from water and exhales air noisy. If this creature should be so fond of its posterity, as the balam, all family of these cats would be dead long time ago. Just this monster, the huge trapperturtle, has laid eggs in nest at the lake coast some days ago.
The balam female hums, having pressed ears to the head, and both cubs depart from water and are hidden behind mother. They observe, how the giant turtle inhales air and dives to the bottom. Cubs will remember this lesson for the future, and they will be very cautious near the water. But other animals can be not so attentive. Thud of hoofs and strange, more similar to donkey roar, neigh announce approaching of donkeyhorse herd to watering place. Striped-legged creatures come into water knee-deep and start to drink greedy. They can do without some water long time, but at an opportunity they drink much willingly. Swift-hoofed animals are too preoccupied with drinking process, and on any time they even lose usual care. Some animals come into water belly-deep. They have already got drunk, and now are simply freshened. One donkeyhorse sprays water by muzzle on itself and neighbours. Simply it is playing. Some other animal join the game whereas others leave on a coast, having got drunk a lot. Water near playing donkeyhorses becomes turbid because of silt and leaves raised from bottom.
The nature does not forgive imprudence, and payment comes almost instantly. One of young donkeyhorses, playing in water, appears snapped at the muzzle by huge trapperturtle. The reptile pulls resting animal in water, and then breaks to it a neck by sharp jerk of the head. The prey body instantly becomes flabby, and the turtle drags it to shallow water.
As against crocodiles, the turtle is able to break off prey under water, not making superfluous movements. Holding carcass by paws, the turtle tears by toothless jaws meat of prey and immediately swallows it. The seductive smell of fresh meat and prey blood spreading in water involves neighbours of the shelled hunter, and soon around of the dead donkeyhorse the scramble begins. Each turtle tries to snatch more fatly and softly piece of meat. Also the reason of it is not only the greed - simply turtles are capable to tear up only rather soft muscular tissues. Bones of large animals they can not bite, though small catch - ducks, fishes, smaller turtles (including neighbours) the trapperturtle swallows as a whole.
Practically in each small pond near to the river one or two such monsters live. They can make life of herbivores intolerable, but the only hope for animals is the fact that the turtle eats only once or two times a week. The full turtle can swim indifferently near to the possible prey, not trying to bite. But the hungry turtle is ready to snap practically any catch, or something that can seem catch.
Balam cats had learned to deceive hungry turtles to drink water in safety. At times they simply wait, while before their eyes the turtle will catch any animal. After that it is possible to approach to water and to have a drink. And if it does not occur, the cat can deceive the trapperturtle by simple way. For this purpose it finds long branch and dips it in water, holding in teeth. Having moved a branch in water, the balam provokes the turtle to attack. When the reptile will snap tree branch, the cat simply lets it off and quickly slakes thirst. While the turtle will understand, that the branch is inedible, the cat already goes away, having slaked thirst in plenty.
The balam female and her two cubs try to avoid places where adult trapperturtles hide, therefore they keep on shallow coast of the river. If the giant will want to hunt them, it will give out itself by all means, slunk to cats in shallow water. However there, where an adult predator will not crawl, its young will do it easily. While the female is occupied with game with one kitten, the second one decides to survey a coast independently. And the first creature which he finds is the one-year-old young of the trapperturtle. This creature in length is only half of balam kitten, but courage and ferocity at it is like one of adult reptiles of these species. The kitten tries to pull out from water this creature by paw. However the tiny turtle does not wish it absolutely and strongly snaps the kitten’s paw.
With a plaintive peep the shaggy cub skips on three paws along the coast, and on the fourth paw the small turtle hangs death grip. At the peep of a kitten his mother already hastens. Having sniffed the turtle which does not hurry up to unclench jaws, the balam female cautiously bites through a head of small predator. Only it is possible to unclench this alive trap.
The cub had tested power of turtle jaws, limps - on his paw it is a strong bleeding cut. But it will be over – wound is not so dangerous, nerves and bones are intact. Mother accurately licks cub’s wound while other cub plays with dead turtle, running on it from behind grass bed. Then the balam female tears off the turtle body and kittens eat meat of the small reptile. However after thirty or forty years such meeting would be finished obviously not by cat’s win.
The full adult trapperturtle is heated on a coast - after nourishing dinner warm and rest are necessary for an animal. It is quiet - at mature age it simply has no enemies. Therefore the predator presumes to fall asleep to itself in full view of all animals. The herd of peccasons walking on a watering place, forces the turtle to open eyes and to look at their side. Animals obviously are nervous - they snort and make no headway, not daring to move. The huge "bearded" male, whose sides are covered with scars from meetings with numerous predators, does not risk to enter fight with the armored reptile. He shakes a head and loudly grunts, loudly trambles down hoofs by the ground. But he does not dare to come close - the trapperturtle opens a mouth wide and extends neck to him. Some time both animals stand facing to each other, but then the turtle unloads a situation: it lazy slips in water and swims, rowing water by powerful paws.
The old leader of peccary herd sniffs at a coast: the turtle had marked the place with its musk secretions. This is the terrible warning of an animal: the monster lives here. And the herd goes to other pond on a watering place, away from danger.
The turtle does not leave far from water, but on plains and in bushes another predator, the balam reigns. If the turtle catches only those creatures which will approach almost in real earnest, the balam catches beforehand chosen prey, pursuing it or concealing from an ambush. And the herd of deermaras grazed among bushes, does not suspect absolutely, that one of them already became object of steadfast supervision of predator. The balam male had hidden among bushes, looking for the most accessible victim. The perception of all predators is arranged so, that they especially concentrate attention to differences from norm. And the balam sees, that one deermara male had strained sinew and is walking somehow gingerly, the old male limps, and the mature female is disturbed with a wound on a shoulder - she constantly licks it by long tongue. Having chosen the prey, the balam waits for an opportunity: he can not compete in endurance with swift-footed rodents, but in speed of a throw it would be hard to find his match. When the deermara female starts to lick a shoulder in dangerous affinity from bushes, the cat is jumping. By impact of paws the balam threw the female of the deermara down on the ground and his jaws were closed on throat of the prey. Animals, to which balam had presented with the life, had run away by long jumps.
When the prey body has become limp, the balam has dragged it to reliable place where nobody will prevent him. Excellent catch has got to him only after several unsuccessful attempts, and the predator is not going to give it up... even if he faces on a track with the whole herd of peccasons. The old "bearded" male, which had driven off the trapperturtle from herd, did not expect such meeting too. Balam can prey the calf of peccason, but to him is impossible to overcome the adult animal. Whole herd is especially dangerous. And still balam does not hurry up to give up hardly preyed deermara. Having put forepaws on the carcass, he loudly roars, hoping to frighten off rather stupid, but strong peccasons. The smell of fresh blood keeps massive herbivores on distance, and they try to miss each other with terribly growling predator. Gradually members of herd one by one go from the blazed track and bypass balam aside. Females push aside calves away from the grinned cat, and terribly snort and wind heads, passing by balam. At last last peccasons run near the predator, and the herd continues to move to plains. Balam does not wish to remain on the track of herbivores too long. He snaps at catch and climbs on large tree. There the animal thrusts carcass in the forked crown of branches and tears off from it a piece of meat. The male balam is hungry, but there are also other animals having the right to this prey. On branches to him the female and her two kittens make the way. Being together, the family of cats starts the meal. Kittens will study long to hunt, and not soon they will catch the first deermara. But they will not stay hungry - wide plains can feed everyone who is able to get food.
Northern America each millennium removes from coast of Europe. But the western side of continent ran into the Asian coast, having formed a mountainous isthmus. And now from Northern America to Asia it is easily possible to get overland. Asia and America during a Cenozoic many times had exchanged representatives of flora and fauna. Therefore in the future such opportunity is not excluded too. But while it is difficult for making - the isthmus is blocked by high mountain ridges, and faunae of continents while develop separately. And this isolation promotes evolution of set of the interesting species perfectly adapted to an inhabitancy.

Trapperturtle (Crococlemys horrida)
Order: Turtles (Testudines)
Family: Chelydridae
Habitat: North America, large river basins - main channels and lakes.

Picture by Dragonthunders

After extinction of crocodiles in different places of a planet various species of water animals began to occupy their ecological niche. In Northern America the huge trapperturtle had became such species. It is the descendant of large alligator snapping turtle (Macroclemys temmincki). Modern alligator snapping turtle is water animal weighting up to 100 kg (usually it grows smaller) and up to 1,5 m long. It eats fishes, alluring them with worm-like shoot in mouth, and then by fast movement catches and "splits" fish by its sharp jaw edges. This creature can attack any overland animal appeared in water. There were cases when such turtles had bit feet of people coming in the pond.
Trapperturtle is the giant among turtles: length of its carapace is more than 2 meters, head is about 40 cm long, length of neck is 0,7 m, tail - 1,5 m, weight of an animal is up to 800 kg. Animals of northern populations usually are smaller, than southern ones. The carapace of animal is substantially reduced, scales do not adjoin with each other. Coloring of the top side of a body is cryptic, gray-brown. At old animals the shell is covered by algae and silt layer improving masking of animal. Paws with powerful claws are well advanced, between fingers there are swimming membranes allowing animal to develop in water the large speed. The head is of the triangular form, its width is more, than length. The head is not involved under the shell, therefore it is protected in addition with some thick corneous plates. Jaws of the turtle are jagged at edges, allowing it to keep and tear apart catch. Eyes are small, located on each side the top part of a head, nostrils are shifted upwards: the turtle can look for catch, having exposed from water only top part of a head. The animal can swallow food only in water. After capture of catch the animal can live without eat one week and more. Shortly before wintering the turtle ceases to eat completely. For acceleration of process of digestion the turtle can get out on a coast and be basked on the sunny place, having extended paws and neck.
Usually the trapperturtle hides in water in deep place near the coast. It can hold the breath on half an hour and more (it depends on temperature of water). When large mammals come on the watering place, the turtle catches the chosen animal for a muzzle, and drowns it, keeping by mouth for enough long time. Thus it instinctively strongly compresses jaws, not soon opening them. Small catch (water birds, small animals swimming in water) turtle catches directly from under water, using long flexible neck.
It is solitary reptile, can gather to groups near catch. Pairing is short, accompanied by short courtship of the male. If near one female two males meet, it causes fight between them, frequently fatal outcome is possible. The male differs from the female in smaller size, larger head and concave plastron. The plastron of the male has brighter and contrast coloring, than at the female: it is bright yellow with black spots. Sides of head of the male are extended in small "hornets".
In the middle of summer the female lays in small hole on sandy coast up to 90 eggs in size with goose ones. The incubating lasts up to an autumn, young turtles hibernate in the nest and dig out on a surface only in the spring. The nest is not protected. The young growth becomes sexually mature at 20-th year of life, lives till 200 years and more.
The alligator snapping turtle is more cold-resistant, than crocodiles, therefore it had life area expanded further to the north. The trapperturtle has inherited from it this feature, meeting practically on all continent from tropics up to places where reservoirs freeze on some time. For winter this species falls to superficial catalepsy at the bottom of river whirlpools. At this time the animal does not emerge on water surface and breathes oxygen which receives through the surface of epithelium of mouth and cloacal bladders.

Peccason (Choerobos robustus)
Order: Even-toed ungulates (Artiodactyla)
Family: Peccaries (Tayassuidae)
Habitat: North America, prairies and edges of forested areas.

Picture by Wovoka

The descendant of gregarious boar-like animal peccaries (Tayassu), one of their species (collared peccary Tayassu tajacu) had inhabited droughty areas of Northern America. Fitness of the present peccary species to life in extreme conditions presumes him to survive during mass extinction and to evolve to new species - the peccason.
Peccason is the large gregarious herbivore mammal, occupying an ecological niche of modern gregarious ruminant animals. Peccaries, pigs and hippopotamuses are non-ruminant artiodactyls, differing from ruminant animals by features of ration and digestion. So, non-ruminant artiodactyls consume more soft and easily digesting forage whereas ruminant animals had have evolutionary success due to the advanced mechanism of digestion of rough and easily accessible forages - graminoids and other grassy plants. Complex four-chamber stomach, in one of which departments the mass of having chewed grass is fermented by the symbiotic unicellular organisms, helps them in this evolution success. However the opportunity of a feed by coarse forages among ruminants is shown by the hippopotamus. At him there is 11-chamber stomach, allowing to digest even rough straw. Therefore it is impossible to exclude completely that the stomach of a peccary (3-chambered) can evolve to more complex one, adapted for digestion of rough forage (if development of such source of a forage will promote a survival).
The peccason is cow-sized one, but it differs by rather short and high body. Head of an animal is massive, high, on a crown there is "crest" of rigid hair sticking upwards, forehead is wide. “Snout” on the end of muzzle is large, it allows the animal to dig out roots from rather soft ground. Characteristic for representatives of family canines are very short: not more long then incisors. It allows jaws to make lateral movements at chewing of grass. Body is covered with short wool of gray-brown color, to winter it becomes thicker and longer. On the neck of male there is “beard” of long white wool.
The animal lives by herds of 10 - 30 animals, during migrations little herds are united to congestions of 300 - 500 animals. In small herd there is a hierarchy, dominant individual usually is the "bearded" skilled male. In large herd separate individuals can pass from one group to another. During breeding season males struggle with each other, drew together and butting each other by foreheads. The dominant male has the right of priority at pairing though subdominant males also have an opportunity to pairing. At the female only one cub in the late spring is born. It remains with mother about one year and is fed with milk up to an autumn, gradually passing to the forage of adult animals.

Donkeyhorse (Asinohippus pseudoequinum)
Order: Odd-toed ungulates (Perissodactyla)
Family: Horses (Equidae)
Habitat: North America, prairies.

Picture by Leonard Popov and Eugeny Hontor

Picture by Pavel Volkov

Can large herbivores mammal ( hoofed mammals in particular) survive in case of mass extinction? Not all of them are capable to do it. The specialized species showing rigid requirements to an inhabitancy, most likely quickly will die out at its change. And among species, satisfied with minimum of the optimal factors easily adapting and adapted to inhabiting in extreme natural conditions, it is possible to find candidates for a survival in conditions of geological and ecological cataclysms. Well-known donkeys (Equus asinus) can become such animals. Real wild donkeys in XX century stand at the edge of extinction, but domestic donkeys due to people had widely settled on Earth. Their became wild descendants are capable to survive in conditions of poor forage and lack of water. Such unpretentiousness also gives them chance of survival.
Existence in Neocene America of the present species of herbivores is result of people activity. In Pleistocene horses had completely disappeared in New World, and only due to people they had appeared there again. Asinohippus (literally: “the donkey horse”) is the direct descendant of become wild donkeys of Northern America. Externally this animal is similar to the large mule, but coloring of it is more similar to coloring of wild donkey. Height of an animal is up to 1,8 m. Body of animal is grey, tail and short mane, and also "belt" on back are black. Legs, belly, "glasses" around of eyes and tip of muzzle are white. On shoulders and hips there are numerous cross black strips. Hoofs are black. The foal (almost always only one foal is born, birth of twins is extremely rare case) is born without strips on legs and with dark, almost black coloring of wool.
Ears of animal are longer than horse’s ones, black, with hairy brushes of long wool on tips: this wool allows to direct to the ear sound waves (as at lynx) better: hearing of an animal is very keen. Eyes are protected from dust and dry winds by rich eyelashes. Muzzle is short and jaws are high; teeth of donkeyhorse are strong, constantly growing. The reason of this feature is animal’s ration: rigid graminoids.
Donkeyhorse keeps on plains and in semideserts by small herds from one dominant male, several females and foals. Young males can form small "barchelor" herds. During the rut between males serious fights for the female harem can be fastened sometimes resulting in fatal outcome. It can run fast and long time, not conceding of the horse in speed. It is capable to not drink about several days, getting moisture from plants. In case of strong thirst animal can dig out of the ground roots and tubers of plants by hoof.

Balam (Dolichofelis gracilis)
Order: Carnivors (Carnivora)
Family: Cats (Felidae))
Habitat: North America, tree and bush stands in areas of temperate and subtropical climate, edges of prairies.

Picture by Viergacht

This species is descendant of medium-sized wild cat jaguarundi (Felis (Herpaliurus) yagouarundi), living now in Central America. The word "balam" from language of Maya indians is meant by "jaguar": this name precisely shows the place of the present animal in nature of Neocene – the role of large predator in life arena.
Similarly to an ancestor, balam has long body and rather short legs: the animal can not pursue catch on big distance and prefers to hunt from an ambush. But the balam size is equal to the size of leopard: length of a body is 150 cm (the height at a shoulder is about 50 cm, waist is higher than shoulders), length of a tail is about 1 meter. Coloring of a wool is dark-brown, but each hair at the basis is darker, and on a tip is lighter. Sometimes on the body of adult animal the pattern of separate spots merging to longitudinal strips is seen. At males the pattern is seen more up, than at females; besides the male is much larger than the female. Tips of paws and lips are white, above every eye there is vertical white strip. The throat and stomach are colored lighter than the back.
Prefers to live in a cross-country terrain, with thickets of bushes, reservoirs (animal swims well), trees (it dexterously clambers on, frequently organizing ambush on tree) and thickets of high grass. Balam hunts small and medium-sized vertebrates, also fishes and turtles. This cat usually keeps by family group: male, female and their kittens.
In pack there are 3 - 4 kittens. They have no expressed spots on wool, paws and lips are dark. Kittens spend the first month of life in shelter: tree-trunk hollow, crevice in rocks, thickets of bushes. They start to accompany with parents in hunting, remaining with them almost before birth of the following pack. If their mother had not become pregnant, cubs can remain in family up to one and half years.