Scientists have made an important discovery in Ganzhou City, Jiangxi Province, southern China. They found the remains of a dinosaur sitting in its nest of fossilized eggs.
The dinosaur, an oviraptorosaur (oviraptor), belongs to a group of bird-like theropod dinosaurs that reached their peak during the distant Cretaceous period (145 to 66 million years ago). Fossils of the adult oviraptor and eggs with embryos have been dated to approximately 70 million years. This is the first time researchers have found a non-avian dinosaur sitting in a nest of fossilized eggs, so they still contain babies inside.
The 70 million-year-old fossil in question: an adult theropod dinosaur oviraptorid sitting on top of a nest of its fossilized eggs. Several eggs (including at least three containing embryos) are clearly visible, as well as the adult’s forearms, pelvis, hind limbs, and partial tail. (Shundong Bi, Indiana University of Pennsylvania)
What do scientists say about the discovery?
Dr. Shundong Bi, of the Center for Evolutionary Vertebrate Biology, Institute of Paleontology, Yunnan University, China, Department of Biology, Indiana University of Pennsylvania, USA, and lead author of the study, told EurekAlert !, “The dinosaurs preserved in their nests are rare, and so are fossil embryos. This is the first time that a non-avian dinosaur has been found sitting in a nest of eggs that retain embryos in a single spectacular specimen.
Although there are some examples of adult oviraptor found in their nests with eggs, this is the first time scientists have found embryos inside eggs. The co-author of the study, Dr. Lamanna, a paleontologist at the Carnegie Museum of Natural History, USA, explains: “This type of discovery, essentially fossilized behavior, is the rarest of the rare dinosaurs. Although some adult oviraptorids have previously been found in the nests of their eggs, no embryos have ever been found inside these eggs.
Dr. Xu, from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, and one of the study’s authors, hopes that this rare discovery will have a lot of information: “It’s extraordinary to think how much biological information is captured in this fossil alone. unique. “Dr. Xu says,” We will learn from this specimen for many years. ”
An attentive theropod dinosaur oviraptoride caves its nest of blue-green eggs while its mate looks at present-day Jiangxi Province in southern China about 70 million years ago. ( Zhao Chuang )
Fossilized eggs were about to explode!
The scientists found an incomplete skeleton of an adult oviraptor with pebbles in the stomach. This is an example of gastroliths, “Stomach Stones,” which the creature had consumed to help her digest her food. It is also the first example of undisputed gastroliths found in an oviraptoride, which the team believes could help provide new information about the diet of these dinosaurs.
The dinosaur was found crouched on the nest of at least 24 fossilized eggs, in a cave or protective posture. This suggests that the dinosaur died while raising or protecting its babies. But when the researchers used oxygen isotope analyzes in the eggs, they found that they had been incubated at bird-like high temperatures, supporting the belief that the adult is likely to die while hatching its nest. .
The partial skeleton of the oviraptorosaur was found in a nest of at least 24 fossilized eggs. ( Bi et al., Scientific Bulletin, 2020 )
At least seven of the fossilized eggs still contain remnants of unex hatched oviraptorid embryos. Based on the development of the embryos, scientists think some of the eggs were about to hatch. According to Dr. Lamanna, “this dinosaur was a worried father who finally gave his life while caring for his cubs.”
The article is published in Science bulletin .
Top image: Representative image of a baby dinosaur in an egg. Source: KtD / Adobe Stock
By Alicia McDermott