Using high-resolution CT scanning and 3D computer imaging, Dr Stephan Lautenschlager from the University of Bristol’s School of Earth Sciences and Dr Tom Hübner from the Niedersächsische Landesmuseum in Hannover have reconstructed and visualized the brain and inner ear of Dysalotosaurus lettowvorbecki, a small, plant-eating dinosaur that lived in what is now Tanzania about 150 million years ago.
Reconstruction of the brain in the young and fully grown Dysalotosaurus lettowvorbecki (Stephan Lautenschlager / University of Bristol)
The paleontologists studied different fossils of the Jurassic dinosaur Dysalotosaurus lettowvorbecki: a very young (juvenile) individual of 3 years and a fully grown specimen of more than 12 years of age.
“The two different growth stages of Dysalotosaurus provided a unique opportunity to study their brain, and how it developed during the growth of the animal,” Dr Lautenschlager explained.
“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,” Dr Hübner added.
By looking at the brain and inner ear anatomy, they found that the brain of Dysalotosaurus underwent considerable changes during growth, most likely as a response to environmental and metabolic requirements. However, important parts responsible for the sense of hearing and cognitive processes were already well developed in the young individual.
Fossil skull of the juvenile specimen of Dysalotosaurus lettowvorbecki (Tom Hübner / Niedersächsisches Landesmuseum Hannover)
“Our study shows that the brain was already well-developed in the young dinosaurs and adapted perfectly to interact with their environment and other individuals,” Dr Lautenschlager concluded.
The findings, published online in the Journal of Evolutionary Biology, have important ramifications for the understanding of how parts of the brain developed in dinosaurs. However, further research is necessary to investigate if the pattern of brain development in individual dinosaurs is also reflected in a large scale trend during the more than 150 million years of dinosaur evolution.
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Bibliographic information: S. Lautenschlager, T. Hübner. Ontogenetic trajectories in the ornithischian endocranium. Journal of Evolutionary Biology, published online May 20, 2013; doi: 10.1111/jeb.12181
