Researchers discover a preserved dinosaur sitting on a nest of eggs with fossilized embryos, a first

The oviraptorosaur fossil was discovered from rocks 70 million years old in Ganzhou City, China, the Carnegie Museum of Natural History (CMNH) said in a January press release.
Oviraptorosaurs were part of a diverse group of feathery, bird-like dinosaurs that lived during the Cretaceous Period.
“Dinosaurs kept on their nests are rare, as are fossil embryos. This is the first time a non-avian dinosaur has been found in a nest of eggs holding embryos in a single spectacular specimen,” said Shundong Bi , a CMNH researcher and professor at Indiana University of Pennsylvania, in the release. Bi and Xing Xu, a professor at the Chinese Academy of Sciences, were the lead authors of a paper announcing the discovery in Science Bulletin.

The fossil of what is believed to be an adult oviraptorid can be seen bent over 24 eggs or more, at least seven of which preserved the bones of the partial embryos found inside, the researchers said in the journal.

Some of the embryos in the eggs were also visible “forearms, pelvis, hind legs and partial tail of the adult,” CMNH said.

“The late developmental stage of the embryos and the adult’s proximity to the eggs strongly suggests that the latter died while hatching from its nest, like its modern cousins, rather than laying its eggs or simply guarding its nesting crocodile. style, as has sometimes been suggested for the few other oviraptorid skeletons found on top of nests, ”said CMNH.

An attentive oviraptorid theropod dinosaur incubates its nest from blue-green eggs as its partner watches in what is now Jiangxi Province in southern China, some 70 million years ago.  Artwork by Zhao Chuang.

The discovery revealed multiple details about the species, including that dinosaurs nurtured their offspring.

“Although a few adult oviraptorids have been found on nests of their eggs before, no embryos have ever been found in those eggs,” said Dr. Matt Lamanna, CMNH chief dinosaur paleontologist and another researcher in the study, in the release.

“In the new specimen, the babies were almost ready to hatch, which tells us no doubt that this oviraptorid has been taking care of its nest for a long time,” said Lamanna. “This dinosaur was a caring parent who eventually gave his life while nursing his young.”

The fossil also gave researchers insight into the diet of oviraptorosaurs, as the fossil was found with pebbles – most likely gastroliths or “stomach stones” – in the abdominal area.

Dinosaurs deliberately swallowed the stones to help them digest their food. According to CMNH, this is the first time that gastroliths have been found in oviraptorides.

“It is extraordinary to consider how much biological information is contained in this one fossil alone,” said Xu. “We will learn from this specimen for many years to come.”

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