Dinosaurs

Extinct in the Cretaceous, 65 million years ago, dinosaurs have captured attention from the smallest to dinosaur paleontologists. It is not surprising, since they are creatures with enormous wingspans that we all like to imagine how one day they roamed freely around our planet. Its origins go back to approximately 240/230 million years ago, which is why they were vertebrates. dominant on Earth for 165-175 million years.

Although the word dinosaur means "terrible lizard" (coined by Richard Owen), did not behave like reptiles as we know them today. In fact, their way of walking was initially bipedal, and even recent research has shown that they could be warm-blooded animals. With a high metabolism, far from what would be expected from a large animal, they would be more agile and would have adapted more quickly to changes than expected. Even, they might have developed social skills, which made them live in herds. Reason that would explain the way in which many of its fossils have been found.

A summary of the beginnings and appearance of dinosaurs

Dinosaurs appeared at the end of the Triassic period. Are the descendants of the archosaurs, the same ones from which crocodiles and birds descend. They arose 20 million years after the great mass extinction of the Permian – Triassic, which wiped out 95% of the life that existed on the planet. It is not known for sure what caused this extinction, but life took a long time to recover due to the great impact it had.

The era in which they existed was the Mesozoic.Also known as the age of the dinosaurs. It extends from 225 to 65 million years ago. It occupies part of the Triassic, and all of the Jurassic and Cretaceous. One of the first dinosaurs was the Eoraptor, a bipedal predator. It is considered to be the common ancestor of all the dinosaurs that ever existed. During the Jurassic, we could find some dinosaurs known as the Diplodocus, which existed between 156 and 145 million years ago. The famous Tyrannosaurus Rex was one of the last species to exist Instead, it lived at the end of the Cretaceous, between 68 and 66 million years ago.

Back then, the climate was much warmer than it is today. About 10 degrees higher. The concentrations of carbon dioxide 4 times higher, probably due to the volcanic eruptions that existed. The terrestrial part, all united in a single continent, Pangea, did not give rise to much coast, so the softening effect of the sea did not exist. The continental climate made the summers very hot, and the winters very cold.

What were the dinosaurs like?

All the information collected today comes from fossil records. Among them they can be bony or not, such as footprints, droppings, feathers, impressions of the skin, and soft tissues and internal organs. In turn, to understand and deduce their behavior and biology, various fields of science come into play. Biology, chemistry, physics and paleontology mainly. Among all of them, from the records found, taking as a reference the knowledge that we have today of other reptiles, birds, and even physics to define their biomechanics, we can understand more closely what they were like.

How big were dinosaurs?

It has been observed that the size of dinosaurs changed between different periods that existed and the region. For example, 80% of the dinosaurs found in the Morrison Formation, in the western United States and where the first fossils were found in 1877, are characterized by Stegosaurus and sauropods. The latter had an approximate average weight of 20 tons, being the largest dinosaurs that ever existed. The fossils found there belong to the Jurassic.

However, recent discoveries such as those of 2015 suggest that the size of the dinosaurs was already much larger than previously thought. All this as a result of a discovery in Argentina in 2015. A new dinosaur skeleton was discovered, the Ingentia Prima. It is estimated that it existed between 228 and 201 million years ago, in the Triassic. It is also estimated that its dimensions would be about 8 to 10 meters in length, with an average weight of 9 tons. This new line explains that evolutionarily, The strategy that made the dinosaurs become giants was much earlier than thought, in fact, it was almost from the beginning that they began to exist. The paradox of this finding is that it had been believed that in the beginning they were small, when really Ingentia Prima is the reason that this belief is not the case.

Most of the fossils have not been excavated, and most of all the dinosaur species that ever existed have not been found or possibly not even remains of them. Their sizes became very variable, such as the gigantic Argentinosaurus, Puertasaurus or the recently found Patagotitan, whose dimensions reached 40 meters and weighed 70 tons. Others, on the other hand, are very small, such as Compsognathus, which was believed in the 90s to be the smallest dinosaur, measuring 1 meter in length and weighing 3-4 kilograms. Recently however, new finds have taken away that "leadership", and even smaller species have been discovered. An example, the Hesperonychus, with a size of 50 centimeters, a weight of 2 kilograms, and a bipedal morphology similar to Compsognathus.

dinosaur behavior

As birds, crocodiles, and dinosaurs descend from archosaurs, there is a fair consensus that many behavioral peculiarities are common. For example, birds and their social behavior living in flocks. The interpretations of this are supported by the way in which many fossil remains have been found, the posture of the skeletons, the habitat, as well as biomechanical simulation by computer.

This herd behavior This became clear already when in 1878 31 Iguanodon skeletons were found together in Belgium. Beyond the reasons that led to group deaths, whether they were falls, prey to another dinosaur, etc. The curious thing is that deposits with skeletons of the same species are frequently found. In addition, another of the signs is that of fossilized footprints, which reaffirm this gregarious and social behavior.

[highlighted] The crests and ruffs of some dinosaurs suggest that they could have been used as a lure for mating and sexual purposes.[/highlighted] The reason for thinking that they were not used for defense is due to their fragility.

On the other hand, attacks between dinosaurs were common. Remains of tail bites have been found, and there are even fossils such as that of a Velociraptor attacking a Protoceratops. Some fossil remains even seem to indicate that cannibalism between some species might have existed. However, certain traits differed greatly among them, depending on their location, their diet, dimensions, locomotion, etc. Something that is reflected, according to the species to which we refer.