Steph Deschamps / December 22, 2021
Scientists announced Tuesday that they have discovered a beautifully preserved dinosaur embryo, dating back at least 66 million years and preparing to emerge from its egg as a bird.
This oviraptorosaurus fossil, discovered in Ganzhou, China, has been named by the researchers Baby Yingliang. This is one of the best dinosaur embryos ever found, Fion Waisum Ma, from the University of Birmingham (UK) and co-author of the study, published in iScience, told AFP.
Baby Yingliang was found with its back bent, its feet on either side of its head, with the latter tucked in on its belly. This position has never been seen before in dinosaurs, but is well known in birds. When chicks are preparing to hatch, they stabilize their head under a wing, while piercing their shell with their beak. Embryos that fail to get into this position have a greater chance of dying from a failed hatch. This indicates that such behavior in modern birds originated with their dinosaur ancestors, explains Fion Waisum Ma.
An alternative might have looked like what crocodiles do, which adopt a sitting posture, with their head only bent over their belly.
Oviraptorosaurs, whose name means egg-stealing lizard, were feathered dinosaurs living in Asia and North America during the Late Cretaceous period. They could have different beak shapes and diets, and ranged in size from monkeys to huge gigantoraptors, measuring eight meters long.
Baby Yingliang measures 27 centimeters from head to tail and rests in a 17 centimeter long egg at the Yingliang Stone Nature History Museum. According to scientists, it is between 72 and 66 million years old, and has probably been so well preserved thanks to a mud slide that buried it and protected it from scavengers. It would have grown to two or three meters long if it had reached adulthood, and would have fed on plants.
This specimen was part of a group of several egg fossils, left out and forgotten for years. Researchers suspected that they might contain dinosaurs and scraped away part of the shell to discover Baby Yingliang. This dinosaur embryo in its egg is one of the most beautiful fossils I've ever seen, said Professor Steve Brusatte of the University of Edinburgh (UK) and a member of the research team in a statement.
The specimen looks exactly like a chick curled up in its egg, providing further evidence that many of the characteristics of birds today derive from their dinosaur ancestors, he added. The researchers hope to study the embryo in more detail using imaging techniques to reveal its entire skeleton.