Two almost perfectly-round dinosaur eggs have been discovered in East China.
The ‘spherical’ eggs were recovered from the Qianshan Basin of Anhui Province, East China, experts say, and date back to the Cretaceous period.
Lasting between 145 million and 66 million years ago, the Cretaceous period was the final time period of the age of dinosaurs.
At the end of the Cretaceous period, dinosaurs were obliterated by a massive asteroid that slammed into Earth.
Two new dinosaur eggs dating back to the Cretaceous period have been discovered in East China. Top (A) shows the two eggs, named QS-01 and QS-02. QS-01 is described as ‘incomplete’ because it is broken and has calcite crystals exposed. Bottom (B) shows the inner and outer surface of QS-01
Researchers say the spherical eggs were recovered from the Qianshan Basin of Anhui Province, East China
EGGS DATE TO THE CRETACEOUS PERIOD
The Mesozoic Era is a the name given to the period from 250 million to 65 million years ago.
The era is divided into three major periods: Triassic, Jurassic and Cretaceous. The eggs date to the Cretaceous period (145 million to 66 million years ago).
Mesozoic was the age of the dinosaurs and lasted almost 180 million years.
The Mesozoic Era followed the Paleozoic Era, during which arthropods, molluscs, fish and amphibians all evolved.
Mesozoic was followed by the Cenozoic Era, during which the continents assumed the configuration that we know today.
The amazing discovery has been detailed by Chinese experts in a new research paper, published in the Journal of Palaeogeography.
‘Here we describe two newly discovered dinosaur eggs from the Upper Cretaceous Chishan Formation in the Qianshan Basin, Anhui Province, East China,’ say the authors.
‘Due to the effects of weathering, the outmost part of the eggshells and the corresponding secondary eggshell units are not preserved in the newly discovered Qianshan dinosaur eggs.’
One of the eggs is complete, named QS-02, while the other, QS-01, is partially damaged and therefore has its interior clusters of calcite crystals exposed.
Both are ‘nearly spheroid’, with a length between 4.1 inches and 5.3 inches and a width between 3.8 inches and 5.2 inches.
‘The outer surfaces of them are weathered and have no obvious ornaments,’ the authors say.
‘The inner surface of the eggshell fragment of QS-01 is covered by a calcite crystal layer and individual calcite crystals are evident.’
According to the team, the eggs represent a new ‘oospecies’ – equivalent to a species, used to classify fossilised dinosaur eggs – called Shixingoolithus qianshanensis.
Previous research suggests that Shixingoolithus likely represents eggs of an ornithopods – small, plant-eating, bipedal dinosaurs.
Ornithopods have been described as ‘bird-hipped’, because of their pelvic structure being a little bit similar to birds. Pictured, Parasaurolophus, a genus of herbivorous Ornithopod dinosaur that lived in the Late Cretaceous Period
Ornithopods have been described as ‘bird-hipped’, because of their pelvic structure being a little bit similar to birds.
The ornithopods flourished from the Late Triassic Period to the Late Cretaceous Period and were one of the most enduring dinosaur clades.
But like other dinosaurs they were wiped out by the Chicxulub impact event – a plummeting asteroid or comet that slammed into a shallow sea in what is today the Yucatán peninsula in Mexico around 66 million years ago.
For those not killed directly by the impact, the collision released a huge dust and soot cloud that triggered global climate change, wiping out 75 per cent of all animal and plant species.
The Chicxulub impact is widely believed to have caused the mass extinction event which made non-avian dinosaurs extinct (concept image)
All non-avian dinosaurs, pterosaurs, ammonites and most marine reptiles disappeared, whilst mammals, birds, crocodiles, and turtles survived.
When the asteroid impacted Earth, it rocked the continental plate and caused huge waves in water bodies, such as rivers and lakes.
These moved enormous volumes of sediment that engulfed fish and buried them alive, while impact spherules (glass beads of Earth rock) rained down from the sky, less than an hour after impact.
KILLING OFF THE DINOSAURS: HOW A CITY-SIZED ASTEROID WIPED OUT 75 PER CENT OF ALL ANIMAL AND PLANT SPECIES
Around 66 million years ago non-avian dinosaurs were wiped out and more than half the world’s species were obliterated.
This mass extinction paved the way for the rise of mammals and the appearance of humans.
The Chicxulub asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event.
The asteroid slammed into a shallow sea in what is now the Gulf of Mexico.
The collision released a huge dust and soot cloud that triggered global climate change, wiping out 75 per cent of all animal and plant species.
Researchers claim that the soot necessary for such a global catastrophe could only have come from a direct impact on rocks in shallow water around Mexico, which are especially rich in hydrocarbons.
Within 10 hours of the impact, a massive tsunami waved ripped through the Gulf coast, experts believe.
Around 66 million years ago non-avian dinosaurs were wiped out and more than half the world’s species were obliterated. The Chicxulub asteroid is often cited as a potential cause of the Cretaceous-Paleogene extinction event (stock image)
This caused earthquakes and landslides in areas as far as Argentina.
While investigating the event researchers found small particles of rock and other debris that was shot into the air when the asteroid crashed.
Called spherules, these small particles covered the planet with a thick layer of soot.
Experts explain that losing the light from the sun caused a complete collapse in the aquatic system.
This is because the phytoplankton base of almost all aquatic food chains would have been eliminated.
It’s believed that the more than 180 million years of evolution that brought the world to the Cretaceous point was destroyed in less than the lifetime of a Tyrannosaurus rex, which is about 20 to 30 years.