Early dinosaurs buried their eggs
(Mirror Daily, United States) – It’s tough to determine habits of animals from millions of years ago, but scientists found that birds inherited their nesting habits from dinosaurs. The extinct creatures, however, have also seen to differences in their behavior along the years. They adapted to circumstances which favored the survival of their young.
Dinosaur eggs are a rare find due to their fragility, but nesting materials have been found to be impossible. Paleontologists have little concrete proof on how the extinct species handled nesting. All that has been left were estimations, and several theories emerged about their habits.
A team of researchers, thus, studied eggshells from 29 different species of dinosaur, comparing them to those from 120 species of modern birds and crocodiles. The two are considered to be the last remaining relatives of the extinct animals, who have been gone for the past 66 million years. Information on their habits could provide with crucial information about their ancestors.
In order to determine the nesting habits, the researchers tested the porosity of the eggshells. For one, birds have eggs with low porosity, which means they have fewer pores that assure the allow the exchange of vapor and gas with the environment. This is due to the fact that modern birds place their nests out in the open.
Crocodiles, on the other hand, have eggs with high porosity that are buried into the ground. This hatching technique results in more pores on the shell to assure better exchange and maintain the unborn animal healthy.
Researchers then took the fossilized eggshells and conducted similarly careful studies regarding their porosity. They found that most dinosaurs, such as sauropods, laid their eggs similar to the crocodiles. They were placed within the ground, covered by mud and vegetation, which resulted in more porous eggs.
However, later dinosaurs, such as theropods have switched their behavior. Instead, their eggs presented with the low porosity of bird eggshells, which mean that they were laid out in the open, likely in constructed frames of material. The more advanced dinosaurs had changed their behavior for the purpose of preservation. Open nested could be moved more easily and placed at higher ground, away from predators.
This is a trait that was not witnessed in the more primitive species of dinosaurs.
However, according to dinosaur egg expert, Darla Zelenitsky, they admittedly do not have an egg from every dinosaur species that once existed. However, they do believe that primitive dinosaurs laid their eggs underground for hatching, while more advances species options for open, fully exposed, and more manageable nests.
Image source: museumvictoria.com.au