Biology of the sauropod dinosaurs: the evolution of gigantism.
Bottom Line: Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates.The extensive pneumatization of the axial skeleton resulted from the evolution of an avian-style respiratory system, presumably at the base of Saurischia.An avian-style respiratory system would also have lowered the cost of breathing, reduced specific gravity, and may have been important in removing excess body heat.
Affiliation: Steinmann Institute, University of Bonn, Germany. email@example.comShow MeSH
Related in: MedlinePlus
Mentions: Body size is one of the most fundamental attributes of any organism (Hunt & Roy, 2005; Bonner, 2006). While some body size maxima (and minima) can be observed and studied directly in living organisms (e.g. the largest trees and the largest marine vertebrates), others have occurred in the geologic past. These must be studied from the fossil record, e.g. the largest insects (giant dragonflies of the Carboniferous), the largest terrestrial predators (theropod dinosaurs), and the largest terrestrial animals ever, the sauropod dinosaurs (Fig. 1). Their uniquely gigantic body size commands special interest from an evolutionary perspective. Sauropod dinosaurs represent a hugely successful radiation of herbivores that originated in the Late Triassic, dominated terrestrial ecosystems in the Jurassic, and flourished until the very end of the Cretaceous (Curry Rogers & Wilson, 2005; Tidwell & Carpenter, 2005). The aim of this paper is to review the evolution of gigantism in sauropod dinosaurs and to discuss and explore hypotheses explaining their unique body size.
Affiliation: Steinmann Institute, University of Bonn, Germany. firstname.lastname@example.org