19. p. 421Theropods and the Origin of Birds
- F. Harvey Pough, F. Harvey PoughProfessor Emeritus, Rochester Institute of Technology
- William E. Bemis, William E. BemisProfessor of Ecology and Evolutionary Biology and Faculty Curator of Ichthyology, Cornell University
- Betty McguireBetty McguireSenior Lecturer, Cornell University
- , and Christine M. JanisChristine M. JanisProfessor Emerita of Biology, Brown University, USA, Honorary Professor of Earth Sciences, University of Bristol, UK
Abstract
This chapter covers the characteristics and systematics of theropods while also considering the origin of birds. It mentions how early theropods were small, agile, lightly built, bipedal carnivores with long arms and legs. The evolutionary history of theropods varies since some gain forms with long and greatly enlarged forelimbs, while other forms against the powered flights in avialans. The chapter provides an overview of the characters and phylogenetic relationships of Mesozoic theropods and descriptions of the major clades. Birds showcase one of the clearest examples of mosaic evolution and exaptation, especially when its changes are not directly linked to the evolution of flight. The chapter also considers the reproduction and parental care among theropods.
