Dinosaur nesting has some similarities to the hatching and incubation behavior of modern crocodiles and the open nests of today's birds, according to study of the ancient creatures' eggs.
The
University of Calgary study, highlighted in the science journal
PLOS ONE, for the first time linked dinosaur eggshell porosity and different types of nesting styles. It also showed how those styles correlated with animals today.
"Dinosaur nest structures and nesting materials are usually not preserved in the fossil record," said Kohei Tanaka, a doctoral student at the University of Calgary and co-author of the PLOS ONE article.
"In the past, this lack of data has made working with dinosaur eggs and eggshells extremely difficult to determine how dinosaurs built their nests and how the eggs were incubated for hatching young," he said.
In the study, Tanaka detailed the egg porosity of 30 different dinosaur species and then compared the results with the egg porosity of 120 species of birds and crocodiles, their closest living relatives.
"Brooding birds, which incubate their eggs in open nests, tend to have low eggshell porosities compared to crocodiles and megapode bird species that incubate in buried nests," said Tanaka.
Most dinosaurs had high-porosity eggs and more than likely buried them, according to
LiveScience.com, but the more developed dinosaurs, like maniraptorans, had eggs with low porosity and used open nests.
"It was probably not until modern-looking birds that open nests with fully exposed eggs came to be," said study co-researcher Darla Zelenitsky, an assistant professor of paleontology at the University of Calgary.
"We don't have eggs for every species of dinosaur, but the more primitive dinosaurs have these buried nests, and the more advanced maniraptoran theropods, which are the closest relatives of birds, laid open-nest eggs that are exposed."
The research could lead to additional work into the various aspects of dinosaur reproduction, said the
Calgary Herald.