Paleontologists Find Fossilized Hadrosaur Nest in Mongolia

The site in the Gobi Desert has been a hotbed of discovery for Late Cretaceous dinosaur fossils, the latest of which are three or four Saurolophus angustirostris babies and two associated egg shell fragments.

It’s not quite Game of Thrones, but scientists have found dinosaur eggs in a place called Dragon’s Tomb in Mongolia.

As per the researchers, these fossils belonged to a group known as Saurolophus angustirostris. The researchers have shared that the remains were found close to fragments of eggshell, which means that the dinosaurs were most probably in the earliest stages of development. This rock looks like it was once part of a nest. “The Saurolophini are the only Saurlophinae to bear supra cranial crests as adults”. They will shed light on how baby duck-billed dinosaurs grew from one foot (0.3 metres) long, to about 40 foot (12 metres) long in adulthood.

Perinatal specimens of Saurolophus angustirostris were recently collected from Dragon’s Tomb. “While hadrosaurids are considered the so-called duck-billed dinosaurs, we saw a very small snout [compared to adults]”, said the study’s lead author Leonard Dewaele from Ghent University in Belgium. “This had been anticipated by other scientists”.

Perinatal specimens of Saurolophus angustirostris: bones on the right side of the block show a certain degree of articulation, whereas bones on the left are disarticulated. These types of hadrosaurs are common around the Dragon’s Tomb region, so there was plenty of reference material. This dinosaur is particularly abundant in the whole Nemegt Formation, comprising approximately 20 percent of all vertebrate fossils found.

While the details of their upbringing remain scant given the obvious passing of time, the researchers say that the nest was most likely situated on a river bank that would have been washed away and covered with sand almost 65m years ago.

Though the fossils were originally poached and sold internationally, the baby dinos have now been returned to Mongolian authorities and are currently housed in the Institute of Paleontology and Geology at the Mongolian Academy of Sciences in Ulaanbaatar.