Inhabitants of the great river

 

Tour to Neocene

 

12. Inhabitants of the great river

 

 

 

During Pleistocene and Holocene tropical rainforests of Amazon basin repeatedly experienced both time of a flowering, and time of oppression. In warm intirglacials the rainforest had occupied hardly probable half of continent, and during ice ages its area was reduced up to several small "islands" among dry and leaf-falling forests. Because of space accident of a late Holocene practically all rainforests had disappeared from the face of the Earth. But after consequences of global ecological crisis have ceased, life began to occupy the left positions again. The great rivers of South America had lost a significant part of tributaries, but had remained deep enough that around of them forests had turned green again. After millions of years the Amason region became “the green hell” again, rich and impassable, as before. And life to this world is given by the river. It irrigates roots of trees, carries seeds and takes out to the ocean thousand tons of sediments, increasing the area of continent. Amazon river has shoaled also its channel was divided to two ones: old Amazon channel and Hyppolite - the river current almost in parallel to Amazon.
The wood growing in Amason region, is a little bit drier, than was before: under pressure of Nasca plate the South-American plate had bent aside Atlantic, and rivers flow to the sea faster, not winding on plain. But in country between Amazon and Hyppolite rivers wood is so damp, as before. Trees stand by roots in seldom drying up swamp, therefore the majority of tetrapod animals inhabits forest canopy at height 20 - 30 meters above the ground. Lianas are stretched between trees. Their stalks are thick and strong, lignescent good, therefore in forest canopy even the large animal can move freely.
Plant practically from any botanic family can become liana. On one of thickest lianas having wide triangular leaves enormous pink funnel-shaped flowers grow – it is former modest bindweed. And on other liana fruits similar to huge violet-brown color pears grow right on the trunk – it is a representative of Ficus genera. Its fruits are edible, and they have already involved one of inhabitants of forest canopy.
Hooked claws of strange creature, hanging downwards the back, orderly clutch at the trunk of fig liana. From time to time the tail similar on monkey’s one clings to near branches. However any idea on an accessory of this animal to monkeys instantly dissipates at look on its skin. From thin brownish wool striped acute spines stick up. They are especially numerous on sides of the beast. It is one of numerous rodents of Neocene, the sidespiny porcupine. The animal moves on manners of the sloth, clinging for a branch by claws. But speed and dexterity of this animal favourably distinguish it from edentate analogue.
The sidespiny porcupine has felt a smell of overripe fruits of fig liana, and now it hurries up for breakfast. Having reached desired fruits, the animal tears them off one by one, and brings to a mouth by paw. incisors accurately get bite through the fruit, and the animal slowly eats it. From time to time the sidespine licks lips by long pink tongue, not giving a precipice to any drop of sweet juice. And losses still happen at him: clumsily having pulled for the next fruit, he casually causes dainties to fall from the branch.
Violet "pear" drops downwards, and with rich splash falls in waters of the small river through which the liana had reached. One second later it slowly emerges and rocks on waves, shining on the sun with ripe side. After some seconds the head covered with an emerald-green scaly skin emerges beside, opens a large-toothed mouth and bites off half of fruit. Convulsively having swallowed juicy pulp, it catches the rest and swallows it, almost not chewing. Then the head slowly looks back and dives into water again.
The scaly owner of a green head is the huge water lizard aquaguana. Grown up to length of 3 meters and more, it peacefully grazes by small groups on thickets of underwater vegetation. Slowly clinging fingers for driftwood and plants, these giants graze soft green of water plants. In the thick belly of blue color the muscled stomach similar to chicken’s one, and the longest 6-meter long intestines are hidden. In the stomach small pebbles pound greens to pulp from which the maximum of nutrients is taken in intestines. Such diet allows the sluggish animal to spend a minimum of time for food search. Having devastated one river bank, the group of lizards swims across the river to another one, allowing vegetation to grow up. They do not eat rhizomes, therefore the vegetation is not exhausted. Such thin out of plants has favorably effect for an oxygen mode: the river does not silting and water flows more freely in it. Besides aquaguanas eat floating water vegetation which shades a river bed.
Eating, aquaguanas as if "walk" in a bottom, moving paws one by one. If it is necessary to swim away, they are swimming, wriggling by all body and having pressed paws to sides. And in case of danger the animal moves away by "breast-stroke" and paddles by strong hinder legs, as if the monstrous long-tailed frog. The large aquaguana practically does not have enemies, but young growth is always on the alert: in the river creatures dangerous to them are found.
From the interlacing of roots the huge two-meter fish with long arrow-like body observes of aquaguanas. Breathing, it rhythmically opens and closes mouth in which sharp, recurved teeth are visible. It is the pikecharacid - piranha, shark and crocodile in one person, a sovereign predator of Amason region waters. Pikecharacids are solitaries actively protecting the territory. But on force and ferocity one such fish is equal to school of piranhas. This fish is the male, it is distinguished with bright red abdominal fins.
Aquaguanas are not needed for the pikecharacid - they are too numerous and in group they can be dangerous. Therefore the young lizard breaking off leaves of a underwater plant in middle of group is desired, but inaccessible catch. But here it is both more accessible and tempting catch.
Aquaguanas are true vegetarians. But their feast is not to taste to numerous inhabitants of thickets - fishes and shrimps. Tens of these tiny creatures hide in thickets from numerous predators, search for livelihood and breed. Shining green and red longitudinal strips, the school of tiny small fishes swims in thickets of underwater grasses. They are neoncichlids - small omnivorous fishes. Some fishes differing by full mouths are males, and they carry in gular sac eggs or larvae. Near to some pairs the big cloud of translucent tiny fries swims. Adult fishes show them sources of food, scattering rotten leaves and ground dust in which crustaceans, worms and infusorians - the forage for fries - are hidden. If any shrimp swims up too close to young growth, adult fishes will drive it off, opening operculums widely and spreading all fins. If such demonstration will not work, the strong push by head will force to recede even the most importunate shrimp.
But not all danger these small fishes can win even for the sake of own posterity. When huge in comparison with fishes muzzle of the aquaguana tears off leaves absolutely beside, neoncichlids prefer to escape. The male utters short click and opens the mouth: it is a signal for fries to be hidden. Immediately all numerous hatch of fries swims together to his mouth, and the fish rescues itself and the precious burden in school of numerous neighbours. Disturbed by large lizards, they try to hide in quieter place.
Small fishes are rescued from giant aquaguanas among roots of trees, but they get in bigger trouble: by sharp throw the pikecharacid catches one of cichlids. The school sharply changes moving direction, gathering to a dense sphere sparkling by colors, and then time turns in shadow and disappears for the sight of predator.
The tiny neoncichlid is no more, than easy snack for this giant. Having swallowed the small fish, the pikecharacid swims near aquaguanas searching for more considerable catch. Its way lies aside a deep gulf on an opposite bank. However this place is already occupied - other pikecharacid, the huge male of almost three-meter length, a giant of this species lives there. And now it is especially intolerant to neighbours: at the bottom of a gulf the deep hole in which the heap of eggs waves is dug out. The careful parent fans eggs by fins and accurately moves away from it rotten leaves and other dust. And fishes risking to swim in a gulf to regale themselves with eggs, make a diet of the vigilant guard.
When the careless neighbour is visible, the careful daddy changes to real dragon. It actively shows itself: having emerged to the surface of water, it opens abdominal fins and trembles them, as if wings of the butterfly. Thus it utters chirring sounds, warning the contender. The stranger male tries to not concede: it also performs an “aria of the butterfly” and trembles by fins. Thus it turns sideways and is stirred up. But the giant daddy is not favour to long "negotiations": it darts off and snaps at the side of stranger. Teeth are closed at half strength, but all the same the decent rag of skin is broken from the side of the attacked fish. Injured large fish lefts the territory away and stands among roots of trees.
Precaution is not superfluous - the smell of blood involves any predators, and with some of them the pikecharacid can not cope. But now on the smell of blood the small fish armored by osseous plates, the leechcatfish, hastens. Fins of this fish work more as hooks, than as oars and rudders. Cautiously having stolen up to the side of the pikecharacid, the strange fish clings to the predator and drops a mouth similar to the sucker to fish’s wound. Quickly moving by jaws, it scrapes the top layer of muscle rags and edges of the torn up skin. But the fish works accurately, it does not tear healthy skin and muscles. Having cleared the wound, the leechcatfish is unhooked and swims away. Now the wound will begin skin over faster and will not inflame.
And the huge pikecharacid in the gulf patrols clutch, not noticing, that larceny of precious eggs occurs directly at it near by. Sand and rotten leaves at the river bottom are moving: under them someone small and long-bodied obviously crawls. From time to time among rotten leaves the pinkish body of a worm-like creature flashes. Near edge of the hole sand starts to move, and already the heap of eggs moves soon. It is visible, as the flat head covered with flat scute, suffices and swallows eggs one by one. When the body of the pikecharacid moves too close above the clutch, the head is quickly hidden in sand, but later the unpunished robbery continues again.
This fish is one more species of catfishes, the wormcatfish. It has adapted to digging habit of life at the bottom of the river and in boggy damp ground of rainforest. Holes of these fishes pass under roots of trees and in thickness of wood litter, sinking to a level of subsoil waters. The wormcatfish eats tiny animals who get in its tunnels. Due to keen sense of smell this fish easily finds motionless food - carrion or fish eggs. It quickly digs under interesting object a burrow from below, and thus it remains unnoticed, and frequently unpunished. On sides of this catfish the line of small osseous plates is located. They are mobile and help fish to creep in holes. As a shovel and a drill the plate on the head and strong forward somactids of the reduced pectoral fins are used.
Wormcatfishes are digging in wood litter on a coast of the river. Sometimes from a layer of fallen leaves the flat head of the fish is put out, and catches snail or beetle. Strong jaws of the fish split their shells with hardly audible crunch. But catfishes are constantly on the alert. They are frightened with any strong concussion of ground. And they appreciablly are nervous, moving by heads asides: fishes are almost blind, but clearly feel someone's steps. And they hasty come back in the dark underground world.
On a wood litter in direction of the river the sidespine goes by clumsy steps. The animal constantly is stirred up and looks small eyes around. He was tortured by parasites, and the animal wants to exterminate them. All prickly animals face with this problem: fine protection against a strong predator at all does not rescue from tiny bloodsuckers. Hedgehogs of Holocene time pinned sour apples on spines and poison parasites with their juice, and the sidespine of Neocene is rescued from parasites by more simple way: he bathes.
The sidespine is good swimmer. He is not afraid of water and willingly has a baths. The animal comes into water up to the neck and starts to be stirred up. Wool is left with bladders of air and water impregnates wool of the beast. Having stood in water a little, the sidespine lies down, having put out from water only a tip of a muzzle and eyes. His needles become covered by set of parasites looking for rescue. Here fleas, ticks and even larvae of small beetles are. All of them caused inconvenience to the beast by their tireless activity, but payment for carefree life had came now.
Translucent shrimps cautiously swim up to the sidespine stood at a coast and start to pick free fare. From time to time the animal is stirred up to wet wool better, and river inhabitants get new portions of parasites.
Shrimps can feel like in safety: large fishes do not touch them near the sidespine, but the sidespine does not suspect, that it is in big danger. His movements have drawn attention of the pikecharacid. The two-meter giant having skin torn off on one side slowly starts to creep to the prickly animal. It yet had not seen such animal, and accepts it for easy catch. Carefully having aimed, the killer fish attacks it by prompt throw... and the same moment jumps aside. In a mouth of the pikecharacid some striped spines are stucks up, and the sidespine thrown off to considerable distance from a coast, hurries up on land. The splash of water under his paws provokes the pikecharacid to attack again, but at this time the animal is ready to defense. The sidespine dives under the head of the pikecharacid and beats it by claws. Then by fast movement the animal emerges and reaches a coast. Coming out on a coast, the sidespine is stirred up and smells air long time then approaches to one of trees and slowly comes back to his native world - to height of tens meters from the ground and water.
The pikecharacid, having received one more wound, leaves under roots of trees. It’ll not remain hungry: the wood gives to a predator plenty of food. Frog, fish, beetle fallen in water - all this ones are quite edible. Sometimes from a tree catch of other sort falls: clapping half grown wings, from a tree the nestling of any bird falls. It can not fly yet, and wings only slow down a little its falling. The splash of water signals the pikecharacid that the table is set. The prompt throw is made - and nestling disappears in the mouth of the large fish.
Flying by above water, adult birds also can become prey of the pikecharacid. The flight of bright birds, frequently flapping wings, flies above quiet water. But suddenly from water the silvery alive arrow jumps off - and one of birds does not reach the saving coast, seized by ruthless jaws.
Aquaguanas, as against the pikecharacid, are harmless, despite of frightening shape. They keep congestions including to secure itself against the killer fish. But they spend in water not all time - having sated, lizards crawl out on sandy spits and banks and have a rest basking at the sun. Warmth is necessary for them for digestion because of it the enzymes secreting with their intestines become more active.
Striped giants behave on a coast, as if first-rate health-resort visitors: they luxuriate laying on stomach or on one side, having spread paws wide. From time to time one of lizards creeps on other place when a shadow from liana or branches closes the sun light to it. Lizards so relax and leave in themselves, that butterflies without fear sit on their heads and their proboscises exhaust liquid which is flowing down from tails of eyes and nostrils of reptiles. It is important for them as gives to insects necessary mineral substances. When the annoying butterfly sits on a head of aquaguana and thrusts a proboscis in tail of an eye of the reptile, the lizard only blinks an eye in answer. When the butterfly bothers the lizard finally, reptile stirs up a head and banishes an insect.
But one of river inhabitants cannot afford to itself so idle life: warm blood demands a lot of food. From the hole in river precipice the short wide muzzle covered with wool appears. It yawns, showing two pairs of lemon-yellow incisors which bottom pair is especially long. After a head from the hole long body on short webbed paws is shown. This creature also is finished by flat wide hairless rosy-brown tail. This animal similar to the otter is the otterodent, the rodent had adapted for water habit of life and a feed by fishes. The animal sniffs at river bank, and then comes into water and dives. Under water it moves excellently: bending body in vertical plane and helping itself webbed hinder legs, the otterodent develops the big speed. Third eyelid of animal is transparent, under water it works, as underwater glasses, allowing to see good.
The otterodent gets out on small island where aquaguanas luxuriate. Its occurrence causes alarm in lizards: some of them have on the body wounds and scars - traces of otterodent attacks. Aquaguanas accept the fighting rack: having turned to a predator back and looking through a shoulder, they start to swing long tails and threateningly to hiss, inflating a red gular sac. The otterodent well knows, how impact of such tail is dangerous: at it(her) under wool on a shoulder the long scar received in youth is latent. Therefore the young fat aquaguana sitting among adult giants, for it(her) completely inaccessible catch.
The otterodent keeps aside of hissing aquaguanas: it bypasses them, slapping by paws on water surface. Completely reasonably it keeps itself from an attack on reptiles and dives again.
In water the otterodent starts to survey thickets of water plants. By experience the animal knows, that a lot of catch is hidden there. And diligence of the woolly fisher is made up: from thickets the young half meter long pikecharacid swims out. The otterodent knows: this fish does not like to swim far, therefore the animal starts to drive the pikecharacid, continuously pursuing it. Some minutes - and by exact impact the otterodent kills dangerous fish. Long incisors of the bottom jaw pierce in a backbone of the pikecharacid from the side, and the top incisors almost bite off a head of fish.
Having griped killed fish in teeth, otterodent leaves on river bank. Here it sits on hinder legs and starts to bite off pieces of the pikecharacid body, holding it by both forepaws. Soon from catch only fins and a large-toothed bony head remain. Having thrown leavings in shallow water, the otterodent comes out. And a head of a creature, which about hour ago was a fear of small inhabitants of this bank, now involves numerous translucent shrimps and fries.
The otterodent does not pay attention to the smallness which had surrounded rests of its catch - it is sated. The animal reaches huge driftwood and gets out on it. Having stirred up, the animal lies down and has a rest, having lowered paws to water. The otterodent has nobody to be afraid, except for the adult pikecharacid. But also the pikecharacid not always risks to be seized with the otterodent: winning in size, it loses in a maneuverability and endurance. Therefore both predators try as it is possible to meet each other’s eye less often, and the woolly fisher quietly can fall asleep under hot beams of the tropical sun.
Here there are rains each day. But many kilometers far from these places, at the north, the rain turns to joyful event from daily routine, and its absence is usual way of life. In deserts of Northern America struggle for water and struggle for life are almost same things.

Bestiary

Leechcatfish (Hirudistomus cataphractus)
Order: Catfishes (Siluriformes)
Family: Loricariidae

Original fish, representative of the family of armored catfishes (Loricariidae). Similarly to the majority of representatives of this extremely diverse family, the fish has mouth modified to scrapping sucker. The majority of its relatives eat microscopic algae, scrapping them from stones and driftwood by such mouth, but the leechcatfish has other gastronomic predilections. This fish prefers carrion, eats meat away from wide wounds of fishes. Sometimes African catfishes Synodontis from family Mochocidae adhere the same diets. But a feed by a carrion is unsafe - bacteria and cadaveric poison can be an absolute obstacle for species starting adaptation to feed by carrion. However at this catfish the fine mechanism of protection was developed: for protection against cadaveric poisins in a mouth of a fish there are glands, producing enzymes and antibiotics. This adaptation has given it one more benefit: attacking on fishes with open wounds on a body, the catfish is more advantageous, than damaging to it, clearing wounds on a body of these fishes. Natural selection has transformed this fish from a predator to the original doctor.
The leechcatfish is the medium-sized fish: the body is about 20 cm long, very thin and long, tail mounts the significant part of length. Pectoral and abdominal fins of a fish are extended, and their forward somactids had changed to dense "brushes" formed from tiny spines. Coloring of the fish is dim: grey background with black strip on back, belly is white. Males have red spot on a back fin. The fish differs by original care of posterity: the male bears spawned eggs on belly.

Wormcatfish (Caecodoras vermiformis)
Order: Catfishes (Siluriformes)
Family: Doradidae



This is high-specialized species of armored catfishes family (Doradidae). The fish had descended from bottom-dwelling catfishes and has gradually adapted to life in a thickness of silt and ground. Body is scaleless, pinkish-colored, up to 30 cm long, width is up to 3 cm. Skin on belly is thin, through it some interiors of the fish are perfectly visible. On a head there is the shell plate, assisting to dig ground: it is the rest of shell covering at modern catfishes of this family all front part of the body. Lateral shell plates had remained and had changed a little - they help to creep in a hole. Due to strong muscles in the basis they can rise and fall, allowing the fish to push off from walls of a hole or to be fixed in them. Almost all fins are reduced, there was only tail fin which somactids were split lengthways and had formed the original "bottlebrush" allowing a fish to push off from walls of a hole. Pectoral fins had almost disappeared - from them there were only very powerful forward somactids, using as the instrument to loosen ground and the device for capture of food - worms and larvae of insects. Eyes of a fish are reduced – they differ only light and darkness. Gills are very small, latent under the valves of skin interfering their chocking up. At a catfish lung and skin types of breath are advanced.
This species can live in water and in damp ground. The catfish digs long tunnels through the wood ground on a water level, therefore in its holes it is always damp also its skin does not dry up.
It is live-bearing species, the female bears from 5 up to 12 fries. First time young fishes live in a layer of silt of small streams with dark water, starting to dig tunnels later.

Dwarf neoncichlid (Nanocichla pusilla)
Order: Percoid fishes (Perciformes)
Family: Cichlidae

Cichlid family (Cichlidae) is one of the most diversified and richly presented families of fishes in Amason region. It includes such known to aquarium-keepers genera of fishes, as Aequidens, Cichlasoma, Astronotus, Pterophyllum, Geophagus and many others. Cichlids of South America are mainly medium-sized and large fishes. But in the future when large species easily can become extinct because of ecological crisis, the role of river giants can easily pass to characids (Characiformes), another large group of American fishes. They will transfer such extinction with rather small damage, we can see plenty of their species today – from tiny and small fishes to some species grew to length of 1 - 1,5 meters. Therefore it is possible, that more numerous characids will occupy ecological niches of cichlids and left to cichlids “extra” roles in ecosystems this way. But the main feature of cichlid behaviour, their care of posterity, will help some survived species of them to compete freely to characids simply spawning in suitable places and sometimes having eaten their own eggs. Therefore in the future it is probable, that these two groups of fishes will exchange leading roles in ecosystems.
The dwarf neoncichlid is one of tiny species of Neocaenic South American cichlids. The length of this fish is about 5 cm, the male is almost 1,5 times larger than the female. Bright neon strips on sides (from above along a lateral line there is green strip, from middle of a body up to a tail fin – red one is) help small fishes to distinguish neighbours and to distract a predator. At males the back is black and a vertical black strip passes through an eye, at females - back is grey, and green lines on sides are wider, than at males. Back fin of the male is higher, than at the female. The neoncichlid is the schooling small fish forming congestions up to 100 ones. The constant leader of school is not present, the school consists of set of breeding pairs, single sexual matured fishes and fries. The male incubates eggs in the mouth, fries of younger age are hidden in the same place at the case of danger. In hatch there is up to 30 - 50 fries, but up to independence only about half of hatch survives. About 2 weeks the young growth is protected by parents, later fishes start to live independently. Fries form separate one-age schools.
Fish eats small invertebrates.

Pikecharacid (Deinocharax esocignathus)
Order: Characids (Characiformes)
Family: Lebiasinidae



Characid fishes (Characiformes) are one of the most successful groups of Amazon fishes in evolutionary relation. Among them there are predators as Serrassalmus, Hydrolycus, Chalceus (in Africa their list Hydrocinus supplements), and exclusively herbivorous fishes Colossoma, Methynnis, Leporinus (in Africa – Distichodus). The majority of characids species includes omnivorous fishes biased in vegetarianism or predating. The majority of characids has the small or tiny size that raises probability of their survival in conditions of reduction of efficiency of biotopes. And ecological plasticity of some characids allows to suppose, that after mass extinction of species the big future expects this group.
The pikecharacid is huge (2 - 2,5 m long) carnivorous characid had replaced in the river predators of Amason region piranhas and crocodiles which had became extinct at the end of Holocene. Such species can not meet by big schools – this fish is extremely territorial, protecting its living area. A body of the fish is arrow-like, back and anal fins are arranged far back. Head is big, flat; the mouth is wide, its edge proceeds up to a vertical of back edge of an eye. Teeth are slightly recurved, numerous, sharp, needle-like. They help to keep the caught slippery catch - fishes and frogs. Body of the fish is silvery colored with a blue shade, back is darker. Abdominal fins are wide with black forward somactids and red spots, and at males they are much longer, than at females. The fish is top-skimmer, and these bright fins are well seen from below: they are used at submission of signals and demonstration of threat. The fish opens them and pulls short sharp movements, accompanying clicking sounds with this demonstration. Eyes are large, yellow-colored. Tips of jaws are black.
This species is the descendant of the trout copein (Copeina guttata), small species of Amazon fishes. From it the pikecharacid has inherited a way of posterity care: eggs are spawned in a small hole at the bottom of the river, and the male protects clutch - up to 20 thousands of large eggs, swollen in water. In 2 weeks large fries hatch from these eggs, and the male abandons them. Fries grow quickly, eating any catch from which they can cope. In 3 years the fish already becomes sexual matured, having grown to length near 75 cm. It lives till 30 years.

Aquaguana (Aquaguana herbivora)
Order: Squamates (Squamata)
Family: Iguanidae



Amazon river of the future will lose many herbivorous inhabitants: large piranhas Colossoma and Myleus eating plants will disappear, and also aquatic mammals manatees already in historical time appeared endangered species. These animals had disappeared because of cold climate in late Holocene epoch. And ecological accident of a boundary of Holocene and Neocene has finished the history of their existence. But herbivores water animals nevertheless have remained in South-American region: they are iguana lizards. They had survived in the rests of bank woods of an Amason region during the ice age, and later had adapted to eat water plants instead of wood vegetation. The iguana swims well, and this ability had very much helped it at development of a new ecological niche.
The aquaguana is the large iguana eating water plants instead of manatees. It keeps by groups on 10 - 20 animals, as rate of eating and growing of plants lizards move upwards and downstream the rivers. The length of the body is 3 - 4 meters, tail accounts half of length. Color of skin is bright-green with thick irregular vertical strips. Such coloring makes the reptile undistinguished in thickets of water vegetation. Belly of the lizard is blue, on a throat there is a folding red-colored gular sac with a cartilage basis attached to jaw bones. When the animal threatens a predator or the contender, the cartilage is spread out also a gular sac becomes good visible. Males are larger, but more thin than females, on a head of the male needle "crest" grows, especially appreciable at old animals. Coloring of the male is brighter, than at the female, and the gular sac is larger. Jaws of the reptile are strong, there are small fleshy cheeks; teeth are leaf-looking with sharp cutting edges, they are closed scissors-likely.
The water habit of life has changed shape of the reptile - membranes between fingers had appeared, back legs became stronger. On tail high skin plica using as tail fin had appeared. A usual way of swimming of the reptile is bending by all body, high-speed habit of swimming is the "breast-stroke" similar to frog kind of swimming. At an attack of the predator in water the reptile tries to swim out and climb out on land where lizard has advantage in might: it protects itself in in-fighting by strong tail impacts. The seized aquaguana bites and scratched by strong claws.
The aquaguana lays eggs (up to 40 ones in size with goose egg) in wood litter and does not protect place of nesting. Young lizards emerge after 2 months of incubation, length of the newborn aquaguana is about 20 cm. In 5 years the lizard becomes adult.

At the Caribbean Islands one species of land iguana Cyclura had evolved to dominating predator in ecosystem.

Otterodent (Pseudolutra praedonis)
Order: Rodents (Rodentia)
Family: Neoichthyomyidae

In historical time in Brazil large fish-eating mammal - the huge otter (Pteronura brasiliensis) lived: its length was up to 2 m and more including tail. At approach of ecological cataclysms and extinction of a plenty of water animals this species had become extinct. Besides its number was undermined by unlimited hunting of people. Standing empty ecological niche was occupied with uniquitous rodents, and the ancestral species with all inclinations for this changing was the contemporary of otters.
The otterodent is the rodent, the descendant of small South-American aquatic rats Ichthyomys. This animal had considerably increased in size in comparison with ancestors: the otterodent is up to 1,5 m in length. Hairless tail (it makes 1/3 length of a body) is flat and serves for swimming - the animal moves, bending backbone in vertical plane. Hinder legs are oar-like, with long fingers and advanced swimming membranes; forepaws have well advanced fingers, with their help the animal holds large catch. wool is dark brown, water-proof, greased with fat from special glands in axillary area. At an adult animal a chest and throat are white. Head is flat, front department of skull and jaws are short, jaw muscles are very strong. Incisors have lemon-yellow coloring of enamel. Bottom incisors are very long, jaws are capable to be opened very widely. It is connected to a way of killing of large catch: the otterodent sticks bottom incisors in a backbone of prey, and then puts bite by top incisors, gnawing through the backbone of catch.
Otterodent feeds by fishes and water animals catching in thickness of water, pursuing it actively. Molluscs and crustaceans are digging by animal out of sand by sharp-clawed forepaws.
This is the solitary animal, only female and her cubs live together any time. Adult animals keep together only during time necessary for pairing, for some hours. This time the male can look after the female, feeding her with fish. Pregnancy lasts about 4 months, there are 3 - 5 cubs in pack. Females with cubs can be met at any time of year, but it is more often at the end of rain season when rivers are especially rich in fishes. Lair is wide hole in river bank, at the female with cubs the hole is deeper, than at the male, but the entrance is smaller, that preserves cubs against the males inclined to cannibalism.

Sidespiny porcupine, the sidespine (Bradycoendou laterispinus)
Order: Rodents (Rodentia)
Family: Erethizontidae


Picture by Amplion

When rainforests of Amason region had practically disappeared, the huge amount of alive creatures, inhabited their, had became extinct. When the Earth had recovered after change of epoch, the damp climate had caused new rainforests to life. And the Neocene fauna which has occupied them, represents a mix of relic Holocene rainforest inhabitants and descendants of animals of leaf-falling and evergreen dry woods adjoining to pampas. Some species had the big successes in development of new habitats. The sidespiny porcupine, the large climbing rodent is also among them.
Specialization to climbing at these species is high-grade: the animal suspends itself on trees with the help of hooked bent claws similar to wood sloths of Holocene and some Madagascar lemurs of Pleistocene. The animal looks like sloth, but as against it has the prehensile tail assisting at tree-climbing. Besides the sidespiny porcupine moves on trees much faster, than the sloth. Paws of animal are very long and muscled, the neck is too lengthened, allows an animal to eat leaves, hanging on a branch from below. Mobility of cervical vertebrae is very great: the head of the porcupine can make almost full turn around. Jaws are short, incisors have orange enamel. The porcupine eats leaves and fruits of plants, sometimes ravages bird nests and eats frogs. As against sloth, the porcupine can move on the ground on slipped feet, thus claws of an animal are directed by ends under the body, and the support falls to external edge of foot and hand. The animal swims not so bad and frequently goes down to water to exterminate parasites difficult for combing them out from wool.
Wool is brown, rather thin, spines are striped, brown and white. Most of all spines are grown on sides of the animal, in middle of a back along a backbone there is a strip of the wool, almost devoid of spines. The stomach of an animal is devoid of spines completely.
The porcupine lives in forest canopy at height of 20 - 30 meters above the ground, preferring areas of wood near to water. It keeps by groups of 3 - 4 animals, adult males frequently live alone. The breeding season begins in the middle of a dry season, only cub is born to a damp season when there is abundance of food. The cub is born very much advanced, with opened eyes. In one week after birth it already tries food of adults, and in 2 months manages without parent milk. In 5 months it is completely independent, though keeps near to mother up to the age of one year.

Some endemic species had descended from wood porcupines at the Caribbean Islands.

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