The study reported that the fossilized remains of a dinosaur perched on a nest of eggs, complete with embryos preserved inside, were excavated from China.
The find – a first world – is an oviraptorosaurus, one of a group of bird-like, theropod dinosaurs that thrived during the Cretaceous between 130-66 million years ago.
According to the experts, the sample in question was found in 70 million year old rocks that were excavated near the train station in the city of Ganzhou, in Jiangxi province.
The adult oviraptorosaurus is partially conserved and hatches over the clutch of at least 24 eggs, of which at least seven contain skeletal remains of the untrained young.
The development of the embryos in the late stage enabled the paleontologists to rule out the possibility that the adult died while laying his eggs.
Instead, the finding indicates that oviraptorosaurs hatched their nests like their modern bird cousins - rather than just guarding their nests on a crocodile.
This was supported by oxygen isotope analyzes of the eggs, which indicated that they are incubated at high temperatures, just like modern birds.
A study reported that the fossilized remains of a dinosaur perched on a nest of eggs, with embryos preserved inside, were exhumed.
The adult oviraptorosaurus is partially conserved and hatches over the clutch of at least 24 eggs, of which at least seven contain skeletal remains of the untrained young. In the photo: a photo of the fossilized specimens, left and for illustration, right
“This kind of discovery – essentially petrified behavior – is the rarest of the rarest in dinosaurs,” said author and vertebrate paleontologist Matthew Lamanna of the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.
“Although some adult oviraptorides have been found on nests of their eggs before, no embryos have ever been found in the eggs.”
“In the new specimen, the babies were almost ready to hatch, which no doubt tells us that this oviraptorid has been caring for its nest for a long time.”
“This dinosaur was a caring parent who eventually gave his life while raising his young,” he concluded.
Analysis of the fossil embryos shows that some, though all well-developed, have reached a more mature stage than others, suggesting that they would probably have hatched at slightly different times if they had not been buried and fossilized.
This feature – which experts call ‘asynchronous hatching’ – appears to develop independently in oviraptorous dinosaurs and some modern birds, the researchers explained.
The team also found a group of pebbles preserved in the abdominal region of the adult oviraptorid, which they say are gastrolytes, or ‘stomach stones’ that would be swallowed to help the dinosaur digest its food.
This is the first time that verified gastrolytes have been stored in a petrified oviraptoride, which could lead to new insights into their diets.
The development of the embryos in the late stage enabled the paleontologists to rule out the possibility that the adult died while laying his eggs. Instead, the finding indicates that oviraptorosaurs hatched their nests like their modern bird cousins - rather than just guarding their nests on a crocodile. Pictured is a cut-out diagram of the adult oviraptorosaur skeleton (with preserved bones in white) hatching its egg clutch
Analysis of the fossil embryos (photo) showed that although all were well developed, some reached a more mature stage than others, suggesting that, they would probably have hatched at slightly different times if they had not been buried and fossilized. .
“It’s extraordinary to think how much biological information is captured in this single fossil,” said vertebrate paleontologist Xing Xu of the Chinese Academy of Sciences in Beijing.
“We will learn from this copy for many years to come,” he added.
The full findings of the study were published in the journal Science Bulletin.
The model in question was found in 70 million-year-old rocks excavated near the train station in Ganzhou, Jiangxi Province.