The 70-million-year-old fossil preserves the embryonic skeleton of an oviraptorid dinosaur, which has been nicknamed Baby Yingliang after the name of the Chinese museum that houses the fossil. Baby dinosaur bones are small and fragile and are only very rarely preserved as fossils, which makes them a very lucky find, said Darla Zelenitsky, associate professor in the Department of Geosciences at the University of Calgary in Canada.
“It’s an amazing specimen … I’ve been working on dinosaur eggs for 25 years and haven’t seen anything like it yet,” said Zelenitsky, co-author of the research published in the journal iScience on Tuesday.
“Until now, little was known about what went on inside a dinosaur egg before it hatched, as there are so few embryonic skeletons, especially those that are complete and preserved in a pose of life, ”she said in an email.
The egg is approximately 17 centimeters (7 inches) long and the dinosaur has been estimated to be 27 centimeters (11 inches) long from head to tail. Researchers believe that in adulthood, if he had lived, he would have been about two to three meters long.
Researchers from China, the UK and Canada studied the positions of Baby Yingliang and other previously discovered oviraptorid embryos. They concluded that dinosaurs move and change poses before hatching in a manner similar to baby birds.
In modern birds, such movements are associated with a behavior called folding, which is controlled by the central nervous system and is essential for successful hatching.
“Most known non-avian dinosaur embryos are incomplete with disarticulated skeletons (bones separated at the joints),” said Waisum Ma, lead author of the study and researcher at the University of Birmingham, UK. , in a press release.
“We were surprised to see this beautifully preserved embryo inside a dinosaur egg, lying in a bird-like posture. This posture had not been recognized before in non-avian dinosaurs.”
All birds have directly evolved from a group of two-legged dinosaurs called theropods, whose members include the towering Tyrannosaurus rex and the smaller velociraptors.
Pre-hatch behavior isn’t the only behavior modern birds have inherited from their dinosaur ancestors. The same type of dinosaurs are also known to sit on their eggs to incubate them in a manner similar to birds, Zelenitsky said.
The fossil was found in China’s Jiangxi Province and acquired in 2000 by Liang Liu, director of a Chinese stone company called Yingliang Group. It ended up in storage, largely forgotten until about 10 years later, when museum staff sorted the boxes and dug up the fossil during the construction of the Yingliang Stone Natural History Museum. The museum is subsidized by the company.