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Hydromedusa - Neocene Project

By electreel
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Elasmosaurine hydromedusa (Herpetomedusa elasmosauroides)
Order: Turtles (Testudines)
Family: Snake-necked turtles (Chelidae)
Habitat: rivers of tropical zone of South America.
Sometimes successful types of anatomy met in any group of animals, can be successfully shown in another one, though in another form. This situation had taken place at Neocenic water turtles of South America: among them one absolutely unusually looking creature had appeared more similar to plesiosaurs for a long time missed from face of Earth. Turtles are rather conservative by their anatomy group of reptiles, but features of their structure have permitted developing of such original design.
The inhabitant of great rivers of South America, the elasmosaurine hydromedusa, is externally very similar to any dwarfish plesiosaurus: the neck length one and half time surpasses length of carapace. It precisely repeats principle of constitution of this sea reptile: long flexible neck permits to seize dexterously the most agile catch under water, and the massive body serves as reliable point of support, allowing making throw. In cervical of this turtle the number of vertebrae is increased (up to 30 vertebrae), and joints between them are improved; due to it neck has got significant flexibility and mobility. But such structure has the return side: head of this turtle can not retract under carapace. But this reptile lives far from coast, in thickness of water, and large predators of South-American rivers, able to harm it, prefer coastal habitats.
Elasmosaurine hydromedusa is adapted to pelagic habit of life: it is tireless swimmer seldom getting out on riverbank. Extremities of this turtle are oar-like, wide and long, and lengthened fingers form similarity of flippers. At males on forepaw two long thick claws are advanced, and on hips of hinder legs there are long corneous heels. The reptile moves basically due to simultaneous flaps of forepaws, hinder legs during swimming serve as rudders. To improve this animal covered with carapace, keeping in water easily and do not sink, under carapace thick layer of fat serving as float is accumulated. Additional buoyancy to turtle is given with the porous bones impregnated with fat, and voluminous lungs. Horn plates of carapace at this turtle in youth are as thick and strong, as at other turtles of comparable size, but at the adult reptile they are appreciably thinner, than at other turtles. Length of carapace is about 1.7 m, weight of adult animal is up to 250 kgs. Tail at this turtle is short, serving basically for storage of fat stock.
Scutes of carapace of the elasmosaurine hydromedusa are smooth and skintight to each other. On medial scutes of carapace at turtles there are small vertical keels, at males a little more sticking up, than at females.
The top part of carapace at the elasmosaurine hydromedusa is colored light brown with darker spots in the centre of each scute. Abdominal shell (plastron) is white with contrast black spots. Neck and extremities at the adult turtle are colored gray-blue with dim white longitudinal strips, at young individuals – dark-brown with grey-green strips. At males an iris of the eye is red, at females it is pale yellow.
Head of the elasmosaurine hydromedusa is wide with strong jaws. Males are more “large-headed”, than females. Edges of jaws are sharp, cutting, and tips of jaws are bent like beak. This turtle eats fishes and other water animals. Young turtles of this species search for water insects, river shrimps and crabs. They live in coastal zone (it is the reason of their darker colouring in comparison with adult reptiles) and do not compete to larger representatives of the species. Growing up, they start to hunt fish in thickness of water and to develop deep-water sites of the river. Adult turtles live far from coast and eat mainly fishes. They also can catch water birds (seizing them from below from under water) and eat corpses of sunken animals. The elasmosaurine hydromedusa almost does not creep to land, only sometimes it has a rest, having clung by paw to trees floating in river or fallen in water.
These turtles are solitary animals meeting together only in pairing season. Because in river it is difficult to mark any conditional borders between sites, turtles simply try to avoid company of each other. Sometimes some turtles surround one large shoal of fishes, but during hunting they operate not together, differing, for example, from dolphins or pelicans.
Hunting turtle tries to catch up planned fish and to push it to water surface. It makes sharp lunges by head, biting fish. Sharp jaws of turtle can literally shear across smaller catch, and to larger animal it puts deep wounds and catches prey weakened from loss of blood. If the preyed fish is too great, turtle simply bites off from it pieces and swallows them. Usually it eats catch while it keeps on water, and does not dive for sunken one. The full turtle has a rest and is basked at the sun, floating on surface of water and occasionally flapping flippers to keep on current.
The pairing season is time when turtles pay attention to the neighbours though any time. Elasmosaurine hydromedusas breed the most part of year, making a break only in dry season. In northern part of area seasonal prevalence in breeding of this turtle is not present. The female ready to pairing emits in water musk liquid, involving males by smelling trace. Sometimes the chain of several males follows such female showing the keenest interest to it. At turtles constant pairs do not form, and female basically is indifferent, what male will be father of its youngs. Males moving by breeding instinct, push away each other from the female, and try to hook by claws for edge of its carapace.
Males never leave water, except for cases when the river or lake where they live, become shallow and dries up. And females annually should make hard way to land to lay eggs. They hardly move overland, dragging massive body forward by flippers, and pushing by back ones. On land the elasmosaurine hydromedusa is very sluggish and clumsy.
However, the female occupied with the nest making, is not defenceless, similarly to sea turtles of Holocene epoch: powerful jaws and long neck allow it to keep nest ravaging lovers at respectful distance. If any predator especially desiring to eggs (for example, the otterodent, large local river rodent) will approach too close, turtle warns of the intention to protect, opening wide mouth and loudly hissing. If threats of the reptile are not taken seriously, it can seize by sharp attack the uninvited visitor and then it is possible to get rid of its stranglehold, perhaps, only having torn off turtle’s head or having left in its jaws a fair piece of own skin. And due to flexibility of the neck turtle can keep all-round defense, simultaneously digging nest for the posterity.
In one clutch it can be up to 20 - 25 eggs. Their incubating lasts more than three months, in colder southern areas delaying up to five months. Young turtles with length of carapace about 5 cm live in shallow wood streams, eating small fishes and shrimps. Dark colouring helps them to mask at the bottom among fallen leaves. For improvement of masking at young turtles on sides of neck and legs skinny scalloped outgrowths develop. Young turtles catch prey by sharp throw of head, not leaving shelter.
At growing up reptiles behavior and shape change: colouring brightens, and young turtle starts to catch fishes, chasing them in thickness of water more often, and, at last, at the age of six years completely turns to pelagic predator. The ten years' turtle becomes able to breed, and the age limit of this species can pass for 130 - 150 years.
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Comments14
anonymous's avatar
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EvanKlein1's avatar
Trendorman's avatar
....turtle..you must take the place of the plesiosaur...the loch ness monster....
Raffyjack's avatar
Why would they need such a long neck and claws? surely its a burden?
electreel's avatar
Maybe, I only followed the description of the creature.
Jaldithas's avatar
good drawing,did you color it?or someone
electreel's avatar
First I coloured it with pencil colours, and then I made the background with Photoshop.
Jaldithas's avatar
hey,its awesome pencil work
juankycorporationsa's avatar
Good drawing, I like much
NEGOXE357's avatar
Very good job, man! Seems so convincing!
electreel's avatar
Thanks a lot! =D it seems that I was inspirated last night!
NEGOXE357's avatar
Yeah, pretty wicked! I could really see this guy somewhere in the evolutionary step.
anonymous's avatar
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