In the Jurassic period, a group of reptiles, known as dinosaurs, came to dominate terra firme environments. They could be found from small animals to gigantic shapes, with more than 10 meters in height, being the most of them herbivorous, but with carnivorous species, which fed on insects and even others dinosaurs.
These days there are only theories that try to explain how dinosaurs reproduced. Some scholars believe that reproduction was sexual and that at least some chicks were born from eggs that females placed in nests or buried in sand or mud. It is not yet possible to say whether these animals maintained mating rituals or competed for their partners, but scientists say that some species exhibited sexual dimorphism.
From some fossil nests found, scientists found that some species of dinosaurs laid their eggs without there was no nest preparation, whereas other species made nests with care, and returned every year for new ones. postures. In some fossilized nests, it may be noted that the nest was built higher than the surrounding ground, which suggests that some species of dinosaurs hatched their eggs just as some birds do these days. current. There is evidence that some species of dinosaurs abandoned their eggs soon after laying, while others did like modern reptiles and kept their eggs warm.
It is not yet known if the dinosaur came out of the egg ready to defend itself, as well as the reptiles, or if it needed the care of parents for some time, as well as birds, but studies say that some species were self-sufficient since the birth.
Recently, a search of dinosaur fossils found a medullary bone in the femur of a Tyrannosaurus rex. This bone is found in birds and serves as an extra reservoir of calcium, a substance that forms the bones and shell of the egg. This finding suggests that at least the Tyrannosaurus rex it was oviparous.
fossilized dinosaur eggs
By Paula Louredo
Graduated in Biology
Source: Brazil School - https://brasilescola.uol.com.br/animais/reproducao-dos-dinossauros.htm