Search Here

A site in China was found to contain 190-million-year old organic remains from non-avian dinosaurs and dinosaur embryos, providing a new insight into how the extinct animals grew to be so large.

Researchers recently discovered hundreds of fossilized dinosaur embryo bones in China's Lufeng County that date back to the Jurassic period roughly 200 million years ago.

They have so far identified the scattered bones of about 20 embryos, all thought to belong to an early species of plant-eating dinosaur called Lufengosaurus.

The study which was published in the journal Nature on Thursday shows the dinosaurs grew very rapidly inside the eggs compared to modern reptiles, possibly to reduce the risk of the eggs being eaten by predators before they hatched. This speedy growth may also clarify why dinosaurs were able to grow to such enormous proportions as adults.

"That's what makes this particularly exciting," said Robert Reisz, a paleontologist at the University of Toronto, Mississauga, and lead author of a study that details the find. "We're looking at different stages of the embryonic life of this animal."

"These are by far the oldest embryonic [dinosaur] materials. [But] we did not find complete eggs. It's a bone bed, which means the bones have been sorted and concentrated, and all of the eggshell materials have been broken up into little pieces."

Prof. Reisz said the remains clearly show the dinosaur embryos grew quickly - not a surprising revelation for dinosaurs, but one that suggests that members of this particular branch of the dinosaur family tree were outpacing others in their ability to attain an impressive body size in short order.

Reisz and his team speculate that the Lufeng site was once located near water and was a popular nesting ground for the dinosaur.

"These animals probably liked to make their nests close to the water because it keeps the sediment in which they lay their eggs fairly moist, so the eggs don't dry out," Reisz said.

"But the danger is that the nests could be flooded, so that's what we presumed happened here: It became inundated, the embryos were smothered by sediment and water, and [they] basically rotted and fell apart."