Fossils of Baby Saurolophus Dinosaurs Discovered at Dragon's Tomb

Posted on October 15, 2015

Saurolophus angustirostris perinatal-fossil

A nest of perinatal Saurolophus angustirostris dinosaurs has been found at the Dragon's Tomb site in Mongolia. The dinosaurs are infant versions of a hadrosaur species. The fossils include three or four baby specimens and two eggshell fragments.

The skulls of the infant hadrosaurs were only about 5% the size of the largest known S. angustirostris specimens. Certain areas of the skull were also not yet fused. The scientists say this suggests these specimens were in their earliest development stages. The specimens did not yet have the characteristic cranial crest at the top of the head.

The research was led by Leonard Dewaele from Ghent University and the Royal Belgian Institute of Natural Sciences, Belgium and his colleagues. Dewaele says in a statement, "The poorly developed crest in Saurolophus babies provides evidence of ontogenetic crest growth within the Saurolophini tribe. The Saurolophini are the only Saurolophinae to bear supra cranial crests as adults."

The scientists have not yet ascertained whether the baby hadrosaurs were still in the eggs or had just hatched when they died. It is believed they were buried by river sediment during the wet summer season. A research paper on the findings was published here in the journal, PLoS One.

Photo: Dewaele et al.