A study has reported that the fossilized remains of a dinosaur sitting on an egg nest, with embryos preserved inside, have been unearthed in China.
The find, for the first time in the world, is an oviraptorosaur, a group of bird-like theropod dinosaurs that thrived 130-66 million years ago, during the Cretaceous period.
According to experts, the specimen in question was found in rocks excavated near the 70-million-year-old Ganzhou City Railway Station in Jiangxi Province.
The adult oviraptorosaur was partially preserved and stretched over the clutch of at least 24 eggs, at least seven of which contain skeletal remains of the non-hatched pups.
The late development of the embryos allowed paleontologists to rule out the possibility that the adult had died while laying eggs.
Instead, the finding suggests that oviraptorosaurs incubated their nests like their modern bird cousins, rather than simply protecting their nests in the manner of a crocodile.
This was supported by oxygen isotope analyzes of the eggs, which indicated that they were incubated at high temperatures just like modern bird eggs.
A study has reported that the fossilized remains of a dinosaur sitting in an egg nest, with embryos preserved inside, have been unearthed in China.
The adult oviraptorosaur was partially preserved and stretched over the clutch of at least 24 eggs, at least seven of which contain skeletal remains from the unincubated pups. In the image: a photograph of the fossilized specimens, on the left, and the illustration, on the right
“This type of discovery, essentially fossilized behavior, is the rarest of the rare in dinosaurs,” said paper author and vertebrate paleontologist Matthew Lamanna of the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.
“Although some adult oviraptorids have previously been found in the nests of their eggs, no embryos have ever been found within those eggs.”
“In the new specimen, the babies were almost ready to hatch, which indicates to us, without any doubt, that this oviraptoride had cared for the nest for a long time.”
“This dinosaur was a worried father who finally gave his life while caring for his offspring,” he concluded.
Analysis of the fossil embryos revealed that while all were well developed, some had reached a more mature stage than others suggesting that if they had not been buried and fossilized, they would have probably hatched at times slightly. different.
This feature, which experts call “asynchronous hatching,” appears to have evolved independently in oviraptorid dinosaurs and some modern birds, the researchers explained.
The team also found a cluster of preserved pebbles in the abdominal region of the adult oviraptorida, which they said were gastroliths, or “stomach stones,” that would have been swallowed to help the dinosaur digest its food.
This is the first time verified gastroliths have been found preserved in a fossilized oviraptoride and therefore may give rise to new ideas about their diets.
The late development of the embryos allowed paleontologists to rule out the possibility that the adult had died while laying eggs. Instead, the finding suggests that oviraptorosaurs incubated their nests like their modern bird cousins, rather than just protecting their nests in the manner of a crocodile. In the picture, a cut diagram of the skeleton of an adult oviraptorosaur (with bones preserved in white) that hatches its egg laying.
Analysis of the fossil embryos (pictured) revealed that while all were well developed, some had reached a more mature stage than others, suggesting that if they had not been buried and fossilized, they would probably have they would have hatched at slightly different times.
“It’s extraordinary to think how much biological information is captured only in this fossil,” said vertebrate paleontologist Xing Xu of the Chinese Academy of Sciences in Beijing.
“We will learn from this specimen for many years to come,” he added.
The full findings of the study were published in the journal Science Bulletin.
The specimen in question was found in rocks excavated near the 70 million-year-old Ganzhou City Railway Station in Jiangxi Province.