About 110 million years ago, in the Lower Cretaceous, lived in the United States Deinonychus, a predatory dinosaur up to three and a half meters long related to the velociraptor. Its fossils have been found in the states of Montana, Utah, Wyoming, Oklahoma, and Maryland. Deinonychus lived in tropical and subtropical swampy forests, similar to the swamps of present-day Louisiana. There were also crocodiles and dinosaurs living there, such as the great predator Acrocanthosaurus and several species of herbivores: the armored Sauropelta, the enormous Sauroposeidon and Tenontosaurus, which we have already talked about in Fossil Zoo.
Deinonychus is bipedal, walking with its body and tail horizontal; He has a height at the hip of about three feet, and weighs about seventy-five kilos. The head, about forty centimeters long, is broad, with a narrow snout and wide-set eyes, giving it good binocular vision. The jaws are strong, with about seventy flat, curved, sharp teeth. It is estimated that each of these teeth was replaced every 290 days. The neck is bent in an S shape, so that the head is higher than the body.
The front legs are quite long; although, as in many carnivorous dinosaurs, his mobility is reduced, they allow him to grab objects. The hands are large, with three clawed fingers on each; of them, the first is the shortest and the second is the longest. The palms of the hands are not facing downwards, as is often incorrectly represented, but are facing each other.
The hind legs are long and strong. The feet have four toes; the former is stunted, but the latter is equipped with a massive sickle-curved claw. This claw, which with its horny covering now missing must have measured about twelve centimeters, is what gives the animal its name: Deinonychus means “terrible claw”, from the Greek terms deinós, “terrible”, and onyx, “claw”. The curvature of this claw is variable between individuals, but it is not clear if it depends on sex, age or other factors. When walking, the claw is kept raised, without touching the ground; only the third and fourth fingers are supported.
The tail is long. The processes of their vertebrae are very long, so that the caudal vertebrae are more than thirteen times as long as they are wide; this, together with the ossification of the tendons, makes the tail quite rigid.
Although no feathers have been found associated with Deinonychus, many of its relatives do, including velociraptor, so it is likely that Deinonychus was covered in feathers. A fossil has been found of an adult, about thirteen or fourteen years old, incubating eggs, which means that it was warm-blooded. The eggs, about three inches in diameter, were blue, not white, probably to better camouflage themselves on the ground, which is where these animals made their nests.
Among the prey of Deinonychus was the tenontosaurus, a herbivorous dinosaur about eight meters in length. Given the enormous size of the tenontosaurus, it has been proposed that Deinonychus hunted in packs, although it is also possible that it was a scavenger, and that the partial skeletons of this predator discovered along with those of its prey, which usually correspond to juveniles, could have been killed. and eaten by their conspecifics in competition for carrion, as seen today among crocodiles and Komodo dragons. Although traces of parallel footprints have also been described that indicate at least gregarious behavior among Deinonychus.
The anatomy of the hind legs is very similar to that of eagles, hawks, and owls. It has been proposed that, like those raptors, Deinonychus used its feet rather than its teeth to kill. It would leap at its prey, grabbing it with its long claws, which dug deep into the flesh, and immobilizing it with the weight of its body, keeping it balanced by its long tail and flapping feathered arms. Then, with the prey still alive, it begins to devour it until it dies from massive hemorrhage and multiple organ failure. The discovery of Deinonychus tooth marks on tenontosaurus bones has made it possible to calculate the force of its bite, which turns out to be greater than that of any living mammal, and at the height of that of an alligator of similar size. From the study of fossilized footprints, a walking speed of about ten kilometers per hour has been calculated. As for his running speed, it is estimated that he reached forty kilometers per hour; they were fast runners, but not as fast as other dinosaurs or an ostrich, for example.
The arms are longer in juveniles than in adults, and the shoulder joint is more mobile. In addition, it is possible that the more curved claws also correspond to the young. These differences may be indicative of different ways of life. It has been proposed that the young were climbing animals and could even fly, while the adults lived exclusively on the ground and had lost the ability to fly. This hypothesis opens new perspectives on the origin of bird flight. The isotope study of the teeth indicates that juveniles and adults also had different diets: juveniles ate mostly small prey, while adults ate large prey. This makes the hypothesis that these animals hunted in groups less credible, unless the packs were made up exclusively of adults, and the young lived apart from their parents.
The first Deinonychus teeth were discovered by paleontologist Barnum Brown in southern Montana in 1931, but they were not properly studied until three decades later, when more complete fossils became available. At the end of the 1960s, paleontologist John Ostrom revolutionized the image of dinosaurs with his study of Deinonychus, showing them for the first time as agile and active predators, and highlighting the similarities of this species with birds. Deinonychus is today one of the best-known predatory dinosaurs, and actually one of the most popular, even if we don’t suspect it. As he himself has confessed, Michael Crichton was based on this dinosaur to create the velociraptors of his novel “Jurassic Park”. He changed the name simply because “velociraptor” seemed more dramatic to him… Real velociraptors are much smaller, about the size of a turkey. So next time you see a velociraptor in a movie, remember that it’s probably actually a Deinonychus. And that it should have feathers.
CONSTRUCTION OF GERMAN FERNÁNDEZ:
reticular infiltrate
Reticular Infiltrator is the first novel in the trilogy The Saga of the Borelians. Do you want to see how it starts? Here you can read the first two chapters.
The Karnak file. Ed.Rubeo
The hanged man and other fantastic tales. Ed.Rubeo