Jiji Press TOKYO (Jiji Press) — Giant dinosaurs weighing two tons may have sat surrounded by their eggs during incubation, a research group led by Nagoya University has found.
Dinosaurs are believed to have tried not to crush their eggs during incubation by arranging them in ring patterns, according to a research paper published on the digital edition of British journal Biology Letters on May 16.
Kohei Tanaka of the Nagoya University Museum, a special researcher of the Japan Society for the Promotion of Science, investigated egg and nest fossils of oviraptorosaur dinosaurs found in China.
Oviraptorosaurs are similar to birds, look like ostriches, and are believed to have walked on two legs. A fossil has been found of a smaller type of oviraptorosaur incubating eggs.
But a larger type of oviraptorosaur, believed to have been eight meters long and weighing two tons, could have crushed its eggs by sitting on them during incubation.
Judging from the eggshell feature of fine holes for breathing, however, the research group concluded that larger oviraptorosaurs did also incubate their eggs, without such methods as burying them in sand.
An analysis of the nest found that larger oviraptorosaurs apparently left a space for sitting at the center of eggs placed in a ring pattern, while smaller species set their eggs without such a space.
While warming eggs appears difficult for the larger oviraptorosaurs with this method, the team concluded that such a style of incubation may have been used to maintain some contact with the eggs while protecting them from enemies and rain.