The dinosaur remains, believed to be about 120 million years old, were unearthed in China

Aug 28, 2014 08:00 GMT  ·  By

A recent paper in the journal Cretaceous Research documents the discovery of what paleontologists believe to be a dinosaur nursery, complete with a babysitter, in China's Lioaning Province.

In their paper, the University of Pennsylvania specialists behind this research project explain that, according to evidence at hand, this nursery is about 120 million years old.

The fossilized dinosaur remains are all packed together in an area measuring just 2 feet (approximately 0.6 meters) across. They belong to 25 specimens, of which 24 were babies at the time they died.

Researchers believe that these 24 young dinosaurs were being looked after by the adult individual whose remains were found next to them. Otherwise put, this mature dinosaur might have been their caretaker.

Based on the size of its skull, which was found to be about 4.5 inches (roughly 11.5 centimeters) long, it was determined that this older dinosaur died around the age of 4 or 5, the University of Pennsylvania researchers further detail.

The creatures' anatomy indicates that they all belonged to a plant-eating species known as Psittacosaurus lujiatunensis. Seeing how these dinosaurs only reproduced after they turned 9, it's unlikely that the adult specimen was one of the babies' parents.

However, it is possible that this larger specimen was otherwise related to the younger ones. Thus, it might have been an older brother or sister entrusted with looking after its baby siblings, specialists write in the journal Cretaceous Research.

Having analyzed the makeup of the rock slab in which these dinosaur remains were embedded, specialists found traces of volcanic material. Hence, they concluded that the babies and their caretaker probably died in the aftermath of a volcanic eruption.

More precisely, chances are that they were killed by a flow of volcanic material. This theory is backed up by the fact that the animals' bodies are all oriented in the same direction. “If they were captured in a flow, the long axis – their spines – would be oriented in the same direction. That was what we found,” says specialist Brandon P. Hedrick.

Due to the fact that their bones do not display any signs of considerable damage, Brandon P. Hedrick and fellow researchers doubt that it was lava that killed these dinosaurs. On the contrary, they argue that the flow that got to them was likely made up of water, mud, rock, and other debris.

Despite evidence indicating that these fossilized remains comprise an ancient dinosaur nursery, specialists are not yet ready to assert that this is indeed the case. “It certainly seems like it might be a nest, but we weren’t able to satisfy the intense criteria to say definitively that it is,” Brandon P. Hedrick wishes to stress.