Biology lab exercise, brain, dinosaurs, endocasts, endothermy & ectothermy, relative brain size
This exercise introduces students to scientific inference. They will infer the mode of thermal regulation of dinosaurs (i.e., were they cold- or warm-blooded?) by comparing the relative brain size of dinosaurs to that of modern vertebrates. In the past 20 years, several lines of evidence have been introduced that suggest that dinosaurs were warm-blooded, not cold-blooded as traditionally thought. The size of the brain relative to the size of the body is one line of evidence. Modern mammals and birds are warm-blooded and have large brains relative to the size of their bodies, whereas reptiles are cold-blooded and have small brains relative to their body size (Martin, 1981). Thus, if we can estimate the relative brain size of dinosaurs we can make inferences as to their mode of thermal regulation; however, since dinosaurs are only known from fossilized specimens (except in Jurassic Park!), we must estimate this value.
Faculty of Humanities & Social Sciences (FHASS)
© Grant R. Hurlburt
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Hurlburt, G. R. (1994). Were dinosaurs cold- or warm-blooded?: An exercise in scientific inference. In C. A. Goldman (Ed.), Tested studies for laboratory teaching, volume 15. proceedings of the 15th annual workshop/conference of the association for biology laboratory education (ABLE)(pp 181-214). New Haven, CT: Yale University, Dept. of Biology.