2014/06/12 by John M. Grady, Brian J. Enquist, Eva Dettweiler‐Robinson +2 · 7 citations
Earth and Planetary Sciences · Environmental Science · #Evolution and Paleontology Studies #Physiological and biochemical adaptations #Amphibian and Reptile Biology
paper · doi:10.1126/science.1253143
openalex publication_date 2014/06/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/23
Were dinosaurs ectotherms or fast-metabolizing endotherms whose activities were unconstrained by temperature? To date, some of the strongest evidence for endothermy comes from the rapid growth rates derived from the analysis of fossil bones. However, these studies are constrained by a lack of comparative data and an appropriate energetic framework. Here we compile data on ontogenetic growth for extant and fossil vertebrates, including all major dinosaur clades. Using a metabolic scaling approach, we find that growth and metabolic rates follow theoretical predictions across clades, although some groups deviate. Moreover, when the effects of size and temperature are considered, dinosaur metabolic rates were intermediate to those of endotherms and ectotherms and closest to those of extant mesotherms. Our results suggest that the modern dichotomy of endothermic versus ectothermic is overly simplistic.