EAPSI:Evolutionary Dynamics of Mesozoic Dinosaur and Mammal Ecomorphology

Gardner Jacob, Bozeman MT

Investigators

Abstract

Dinosaurs and mammals have many similarities, including warm-bloodedness, a global distribution, and diverse body forms and lifestyles. This project will explore the ways in which these two animal groups became diverse and widespread across the globe. The results of this analysis will yield insights into why different animal groups dominate the world's ecosystems and adapt to a large variety of lifestyles. The fellow will measure Mesozoic dinosaur and mammal fossils and calculate muscle lever arms, an indicator of general movement capability. These data will be used to model the rates and patterns of lever arm change over time and test for associations with environmental change. The fellow will visit the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing to work with Dr. Xu Xing, one of the leading experts on vertebrate paleontology, and collect data from Chinese dinosaur and mammal species. The origins of biological innovations, such as terrestrial colonization and powered flight, are pivotal events in vertebrate evolution, and are often coupled with changes in locomotor morphology. Yet, little is known about how the rate of such changes are due to trait-environment interactions. The overall objective of this project is to quantify the rate of locomotor change in Mesozoic mammals and dinosaurs. The fellow hypothesizes that high rates coincide with shifts in physiology and the environment. Dinosaur locomotion has remarkable parallels with mammal locomotion and thus provides a natural experiment for investigating how trait-environment interactions influence biological innovation. We will collect morphological data on the locomotor lever-arms from Mesozoic mammal and dinosaur fore- and hind-limbs. The simplicity of these parameters allows rate shifts to be modeled across clades that would be undetectable using species-specific models. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and China's Ministry of Science and Technology.