Rare Fossils Give Insight Into Development of Dinosaur Brains

An analysis of differently-aged brain fossils from the same species of dinosaur has revealed new insights into how the organ developed in the 150 million year old creatures.

The fossils of two Jurassic-aged Dysalotosaurus lettowvorbecki were studied using high-resolution CT scanning and computer imaging to reconstruct and image the brain and inner ear of the dinosaur. The fossils of a juvenile about three years old and an adult more than 12 years old were prime specimens for researchers to use because of the quality of the fossils and their difference in growth stages, which would likely reveal great differences in brain structure.

Dysalotosaurus was a herbivore about the size of a kangaroo that lived in in the late Jurassic period in what is now called Tanzania.

Researchers found that the Dysalotosaurus  brain underwent considerable changes as it aged- most likely as a response to environmental and metabolic requirements. But important brain parts responsible for the sense of hearing and cognitive processes were already well developed in the young individual, the researchers found.

Stephan Lautenschlager, paleontologist at University of Bristol lead author of the research paper, said the study "shows that the brain was already well-developed in the young dinosaurs and adapted perfectly to interact with their environment and other individuals."

It was fortuitous that researchers were able to conduct their study, as adequate specimens are not easy to come by.

Study co-author Tom Hübner, a paleontologist at the Niedersächsische Landesmuseum in Hannover, Germany, said, "Well-preserved fossil material, which can be used to reconstruct the brain anatomy is usually rare. Thus, we were fortunate to have different growth stages available for our study."

The research was published in the Journal of Evolutionary Biology.