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
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.