Thermophysiology and biology of Giganotosaurus: Comparison with Tyrannosaurus

Abstract

Large carnivorous dinosaurs present many interesting biological and ecological questions. The most important information for understanding the ecology of these dinosaurs is their metabolism and thermal physiology. These factors in conjunction with their body mass determine the quantity of meat these animals needed to consume, how rapidly they grew and behavioral characteristics such as range size and reproduction. Oxygen isotope values of bone phosphate may be used to determine the relative temperature variations experienced by skeletal regions during bone deposition. Temperature variations relate to an animal's thermal physiology and can be used to estimate their metabolic physiology. Previously, we reported and Showers 1994 on the thermophysiology of Tyrannosaurus rex using this methodology. Here, we present the results of the even larger South American carnivorous dinosaur Giganotosaurus carolinii. Comparisons of the isotopic patterns are used as a basis for a preliminary discussion of the biology of these large theropods. Data support the interpretation that both theropods support homeothermy by means of intermediate metabolic rates Copyright: Paleontological Society, October 1999.