François Therrien, paleontologist at the paleontological museum Royal Tyrrell of drum lighterin Alberta, is a co-author of the study published Monday in the American scientific journal Proceedings of the National Academy of Sciences (PNAS), which analyzed eggshells from dinosaurs buried in southern Alberta.
According to him, the study can give a lot of information about what happened during this transformation from a typical meat-eating dinosaur to a bird […]
.
He adds that the transition was gradual, which the researchers found by examining similarities between the dinosaur and modern reptiles and birds.
We were able to understand that the dinosaur produced its eggs very slowly, which is typical of modern reptiles
explain Darla Zelenitskya professor of dinosaur paleobiology at the University of Calgary and also a member of the team that carried out the study.
The researchers were also able to determine the body temperatures of the Troodons and thus better understand the reproductive system of the dinosaur.
Dinosaur nests, some of which have been found at two sites in southern Alberta, had as many as 24 eggs. This suggests that female Troodons may have laid eggs in communal nests.
Now we have analytical support that allows us to argue that these Troodons probably shared their nest
notes Mattia Tagliavento, lead author of the study and postdoctoral researcher at Goethe University in Frankfurt, Germany. Which is a behavior that is now observed in nature
in some birds such as ostriches.
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A piece of eggshell from a Troodon dinosaur. The analyzed fragments were about the size of a fingernail.
Photo: Provided by Darla Zelenitsky
Promising technique
François Therrien says he is surprised at the amount of information that can be gleaned from tiny fragments of eggshell no bigger than a fingernail. For example, eggshells have already been used to estimate the body temperature of some other types of dinosaurs, which varies from species to species.
Mattia Tagliavento notes that the technique can be accurate to plus or minus 4°Celsius.
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Illustration of a Troodon brooding its eggs. Fossil nests have been found with up to 24 eggs, suggesting they were shared by multiple females.
Photo: Masato Hattori
David Varricchio, professor of paleobiology at Montana State University, also argues that the eggshell analysis technique used by the researchers has great potential, but is still in the early stages of development. its application.
He was not involved in the new study, but did one suggesting that Troodons lay their eggs in pairs, depending on their arrangement in the nest.
In this regard, it is noted that female birds have one ovary and they can lay an egg every one or two days, while reptiles have two ovaries, which means they can produce two eggs at a time. times even though they can’t lay eggs as fast as birds. Scientists do not know, however, whether the evolutionary loss of an ovary occurred in non-avian dinosaurs or after the transition to birds.
They are also investigating whether Troodons could have survived in wetlands in different parts of the world, as opposed to the semi-arid regions where the eggs were first discovered.
With information from Emily Chung and The Canadian Press