Prof. Clauss and his colleagues from Germany and the UK studied the shape of the ribcage in 126 terrestrial tetrapods — from prehistoric times up to the present day. With the aid of photogrammetry and computer imaging techniques, they compiled a dataset of digital 3D models of tetrapod skeletons. “This resulted in 126 digital skeletons of tetrapods including 86 synapsids (10 fossil synapsids, or ‘mammal-like reptiles,’ and 76 fossil and extant mammals), 38 diapsids (six extant birds, 27 non-avian dinosaurs, five fossil and extant reptiles), and two amphibians,” the researchers said. Using the computer-based visual evaluation of this dataset, the team reconstructed the volume of the body cavity (torso), which is delineated by the spinal column, the ribcage and the pelvis. “In the overall dataset, diet had a significant effect on the torso volume, with herbivores having about 1.5 times larger torso volumes than carnivores. This was due to a clear effect of diet in mammals,” Prof. Clauss and co-authors said.
The team’s findings were published online Nov. 4, 2016 in the Journal of Anatomy.