Scientists have made an important discovery in the city of Ganzhou in China’s southern Jiangxi province. They found the remains of a dinosaur sitting on its nest with fossilized eggs.
The dinosaur, an oviraptorosaur (oviraptor), belongs to a group of bird-like theropod dinosaurs that peaked during the distant Cretaceous (145 to 66 million years ago). The fossils of the adult oviraptor and the eggs containing the embryos have been dated to about 70 million years old. This is the first time that researchers have found a non-avian dinosaur sitting on a nest of eggs that have been fossilized so that the babies are still inside!
The ~ 70 million year old fossil in question: an adult oviraptorid theropod dinosaur sitting atop a nest of its fossilized eggs. Multiple eggs (including at least three containing embryos) are clearly visible, as are the adult’s forearms, pelvis, hind legs, and partial tail. (Shundong Bi, Indiana University of Pennsylvania)
What do the scientists say about the discovery?
Dr. Shundong Bi, from the Center for Vertebrate Evolutionary Biology, Institute of Palaeontology, Yunnan University, China, Department of Biology, Indiana University of Pennsylvania, USA, and lead author of the study, told EurekAlert! are rare, and so are fossil embryos. This is the first time a non-avian dinosaur has been found sitting on a nest of eggs containing embryos in a single spectacular specimen. ”
While there are a few other examples of adult oviraptor found on their egg nests, this is the first time scientists have found embryos inside the eggs. Study co-author 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 in dinosaurs. Although a few adult oviraptorids have been found on nests of their eggs before, no embryos have ever been found in those eggs. ”
Dr. Xu, of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, and one of the study’s authors, expects this rare discovery to contain a lot of information. only this one fossil. Dr. Xu says, “We will learn from this specimen for many years to come.”
An attentive oviraptorid theropod dinosaur incubates its nest of blue-green eggs as its partner watches in what is now Jiangxi Province in southern China, some 70 million years ago. Zhao Chuang
The petrified eggs were about to hatch!
The scientists found an incomplete skeleton of an adult oviraptor with stones in its stomach. This is an example of this gastroliths, “Stomachstones,” which the creature had eaten to help it digest its food. It is also the first example of undisputed gastroliths found in an oviraptorid, which the team believes could help provide new information about these dinosaurs’ diet.
The dinosaur was found huddled over the nest of at least 24 fossilized eggs, in a brooding or protective position. This suggests that the dinosaur died while brooding or protecting its babies. But when the researchers used oxygen isotope analysis on the eggs, they found they hatched at high, bird-like temperatures, supporting the belief that the adult died earlier while incubating on its nest.
The partial skeleton of the oviraptorosaur was found on a nest of at least 24 fossilized eggs. Bi et al., Science Bulletin, 2020
At least seven of the fossilized eggs still contain the remains of oviraptoride embryos that have not hatched. Based on the development of the embryos, the scientists believe that some of the eggs were about to hatch. According to Dr. Lamanna: “This dinosaur was a caring parent who eventually gave his life while nursing his young.”
The article was published in Science Bulletin
Top image: Representative image of a baby dinosaur in an egg. Source: KtD / Adobe Stock
By Alicia McDermott