Ornitomímidos and Dromeosaurios
The carnivorous dinosaurios very developed numerous specialized characteristics. Some, like Troodom, adapted to the life in the remote north, cold and shady surroundings where the hours of the dark surpassed to those of solar light. In these conditions, good night vision had of being a great advantage in the game of the survival. Other carnivores, like Avimimus, transformed themselves into animals with numerous characteristics similar to the birds, a sign of their slow evolution towards a type of completely new animal.
• Troodon, Cretácico, 70 ms.a. North America, Europe, 2 ms of length
Means carnivore so large, Troodon had a light complexión. The long back legs indicate that probably he was a quick runner who persecuted raudo to his prey, such as small reptiles and mammals. Also it could be an all-consuming one of eggs, because between their teeth have been egg rinds of dinosaurio broken, which makes think that they were part of his diet. Perhaps also one fed on defenseless young of other dinosaurios, sacking the nests when the adults did not watch the litter.
• Sinornithoides, Cretácico, 105 ms.a. Asia, 1.1 ms of length
Sinornithoides, of size similar to the one of a turkey, is one of the carnivorous dinosaurios known smaller. The long back legs indicate that he was a quick runner and the great cerebral cavity of the skull suggests was an intelligent creature. Sinornithoides had a compact body and one long tail in whip form that contributed half of its length overall. Its diet had to be based on small mammals and reptiles, as well as on insects.
• Ornitholestes, Jurásico, 150 ms.a. North America, 2 ms of length
Ornitholestes was an agile carnivore who lived in wooded habitats. It was fed on lizards, small mammals and possibly of the first birds, that appeared during the superior Jurásico. It also could be a scavenging animal that fed itself on the rest of dead animals. The small head of Ornitholestes lodged jaws with sharpened teeth and a snout on which a bony crest grew. In order to balance while it ran, it maintained the tail long and thin raised On guard horizontal and it twisted it towards a side when it wanted to change of direction.
• Avimimus, Cretácico, 80 ms.a. Asia, 1.5 ms of length
Avimimus was dinosaurio of long back members with bird aspect, although really it was not it. Its head was similar to the one of a bird, equipped with a great brain, great eyes and a tip without teeth. The front extremities maintained folds to them near the body, like the birds fold their wings. Although in their case have not been indications of pens, some scientists think that it could have them in the arms, although could not fly, since these were too short to allow the flight. Avimimus was probably omnívoro that it fed on plants and animals, mainly of insects.
• Oviraptor, lived 80 million ago years, Asia, 1.8 ms of length.
This dinosaurio was found in the decade of 1920 on an egg nest, that originally was attributed to Protoceratops, herbívoro of average stature. One thought that new dinosaurio was robbing eggs of Protoceratopss, of there the name of Oviraptor, egg thief. Later, in the decade of 1990, other eggs similar to the previous ones were discovered and, since inside one of them was a young of Oviraptor, the idea that this dinosaurio discarded outside an egg thief. In fact, Oviraptor was on its own nest, where it incubated eggs until his appearance.
The skull of Oviraptor was small and of little weight, with great ocular openings. The most surprising characteristic of its skull was the great bony crest that grew over its nose. The crest probably was covered with corneous substance. Its toothless tip era very similar to the tip of a bird.
Oviraptor was a carnivore of long back legs, tail long and pointed and great eyes. It had powerful front extremities equipped with claws and a tip without teeth. On its head of bird it had had a high bony crest, of uncertain function. The scientists mainly think that Oviraptor was covered by a layer with plumón and that could have had covers some parts of their body with pens, their front members. Their hands were extended and adapted to take root. The three fingers with which they were equipped finished in robust curved claws of about 8 cm in length.
Oviraptor lived in a semidesert barren habitat, can that in group. The long back extremities indicate to us that it had of being quick. If he were something similar to a present ostrich, could reach speeds of up to 70 km/h in short sections. The most remarkable aspect of its way of life is that it incubated his eggs, which makes think that the parents of Oviraptor took care of of their small ones.
Oviraptor constructed a sand nest to which it gave crater form. In center of the crater it put its eggs in circular disposition, between 15 and 20, of oval and extended form.
Oviraptor was a quick animal that could pursue to small prey, to which it would kill to pecks and tiny amounts with the tip. The form of its tip indicates that it could have fed on plants, in which case would be omnívoro, an animal that feeds on plants and animals.
Ornitomímidos
There was a group of dinosaurios with an appearance very similar to the present ápteras birds (the ostriches, the emúes and the hens). One is the ornitomímidos ones, that mean imitadores of the birds. They had long, clearly suitable back extremities for the speed, tips without teeth and esbeltos front members with prensiles hands. The dinosaurios of this group populated numerous regions with the world.
• Ornithomimus, Cretácico, 70 ms.a. North America, 3.5 ms of length
• Gallimimus, Cretácico, 70 ms.a. Asia, 6 ms of length
• Deinocheirus, Cretácico, 70 ms.a. Asia, unknown length
• Struthiomimus, Cretácico, 70 ms.a. North America, 3.5 ms of length
Dromeosaurios
The scientists call dromeosaurios, that mean running lizards, but exists for them a known name more: raptores. The dromeosaurios are between the most fierce dinosaurios, equipped with feet of long flagelantes claws and great and prensiles hands. According to the present knowledge, these dinosaurios were the ancestors of the birds. Some dromeosaurios could have pens, and their arms could have evolved until giving rise to wings.
• Velociraptor, Cretácico, 70 ms.a. Asia, 1.8 ms of length
• Pyroraptor, Cretácico, 70 ms.a. Europe, 1.8 ms of length
• Dromaeosaurus, Cretácico, 70 ms.a. North America, 1.8 ms of length
• Utahraptor, Cretácico, 125 ms.a. North America, 6.5 ms of length
• Deinonychus, 110 ms.a. North America, 3 ms of length
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