Fossilised remains of dinosaur sitting on eggs with embryos inside found in China


The fossilised remains of a dinosaur sitting on a nest of eggs, complete with embryos preserved inside, has been unearthed from China, a study has reported.

The find — a world first — is an oviraptorosaur, one of a group of bird-like, theropod dinosaurs that thrived from 130–66 million years ago, during the Cretaceous Period.

According to the experts, the specimen in question was found in 70 million-year-old rocks excavated near the railway station in Ganzhou city, in Jiangxi Province.

The adult oviraptorosaur was partially preserved brooding over the clutch of at least 24 eggs, at least seven of which contain skeletal remains of the unhatched young.

The late-stage development of the embryos allowed the palaeontologists to rule out the possibility that the adult had died while laying its eggs. 

Instead, the find suggests oviraptorosaurs incubated their nests like their modern bird cousins — rather than just guarding their nests in the manner of a crocodile.

This was supported by oxygen isotope analyses of the eggs, which indicated that they were incubated at high temperatures just like modern birds eggs.

The fossilised remains of a dinosaur sitting on a nest of eggs, complete with embryos preserved inside, has been unearthed from China, a study has reported

The adult oviraptorosaur was partially preserved brooding over the clutch of at least 24 eggs, at least seven of which contain skeletal remains of the unhatched young. Pictured: a photograph of the fossilised specimens, left, and in illustration, right

‘This kind of discovery — in essence fossilised behaviour — is the rarest of the rare in dinosaurs,’ said paper author and vertebrate palaeontologist Matthew Lamanna of the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania.

‘Though a few adult oviraptorids have been found on nests of their eggs before, no embryos have ever been found inside those eggs.’

‘In the new specimen, the babies were almost ready to hatch, which tells us beyond a doubt that this oviraptorid had tended its nest for quite a long time.’

‘This dinosaur was a caring parent that ultimately gave its life while nurturing its young,’ 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, had they not been buried and fossilised, they would likely have hatched at slightly different times.

This characteristic — which experts dub ‘asynchronous hatching’ — appears to have evolved independently in oviraptorid dinosaurs and some modern birds, the researchers explained.

The team also found a cluster of pebbles preserved in the adult oviraptorid’s abdominal region, which they said are gastroliths, or ‘stomach stones’, which would have been swallowed to help the dinosaur digest its food.

This is the first time that verified gastroliths have been found preserved in a fossilised oviraptorid and thus may lead to new insights about their diets.

The late-stage development of the embryos allowed the palaeontologists to rule out the possibility that the adult had died while laying its eggs. Instead, the find suggests oviraptorosaurs incubated their nests like their modern bird cousins — rather than just guarding their nests in the manner of a crocodile. Pictured, a cutaway diagram of the adult oviraptorosaur skeleton (with preserved bones in white) brooding its egg clutch

The late-stage development of the embryos allowed the palaeontologists to rule out the possibility that the adult had died while laying its eggs. Instead, the find suggests oviraptorosaurs incubated their nests like their modern bird cousins — rather than just guarding their nests in the manner of a crocodile. Pictured, a cutaway diagram of the adult oviraptorosaur skeleton (with preserved bones in white) brooding its egg clutch

Analysis of the fossil embryos (pictured) revealed that, while all were well-developed, some had reached a more mature stage than others suggesting that, had they not been buried and fossilised, they would likely have hatched at slightly different times

Analysis of the fossil embryos (pictured) revealed that, while all were well-developed, some had reached a more mature stage than others suggesting that, had they not been buried and fossilised, they would likely have hatched at slightly different times

‘It’s extraordinary to think how much biological information is captured in just this single fossil,’ said vertebrate palaeontologist Xing Xu of the Chinese Academy of Sciences in Beijing. 

‘We’re going to be learning 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 70 million-year old rocks excavated near the railway station in Ganzhou city, in Jiangxi Province

The specimen in question was found in 70 million-year old rocks excavated near the railway station in Ganzhou city, in Jiangxi Province

HOW THE DINOSAURS WENT EXTINCT AROUND 66 MILLION YEARS AGO

Dinosaurs ruled and dominated Earth around 66 million years ago, before they suddenly went extinct. 

The Cretaceous-Tertiary extinction event is the name given to this mass extinction.

It was believed for many years that the changing climate destroyed the food chain of the huge reptiles. 

In the 1980s, paleontologists discovered a layer of iridium.

This is an element that is rare on Earth but is found  in vast quantities in space.  

When this was dated, it coincided precisely with when the dinosaurs disappeared from the fossil record. 

A decade later, scientists uncovered the massive Chicxulub Crater at the tip of Mexico’s Yucatán Peninsula, which dates to the period in question. 

Scientific consensus now says that these two factors are linked and they were both probably caused by an enormous asteroid crashing to Earth.

With the projected size and impact velocity, the collision would have caused an enormous shock-wave and likely triggered seismic activity. 

The fallout would have created plumes of ash that likely covered all of the planet and made it impossible for dinosaurs to survive. 

Other animals and plant species had a shorter time-span between generations which allowed them to survive.

There are several other theories as to what caused the demise of the famous animals. 

One early theory was that small mammals ate dinosaur eggs and another proposes that toxic angiosperms (flowering plants) killed them off.  



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