23 3 The Anatomical Foundation for Multidisciplinary Studies of Animal Limb Function: Examples from Dinosaur and Elephant Limb Imaging Studies John R. Hutchinson 1 , Charlotte Miller 1 , Guido Fritsch 2 , and Thomas Hildebrandt 2 all we have to work with, at first. Y et that does not fi mean that behavior cannot be addressed by indi- rect scientific means. fi Here we use two intertwined case studies from our research on animal limb biomechanics, one on extinct dinosaurs and another on extant elephants , to illustrate how anatomical methods and evi- dence are used to solve basic questions. The dino- saur study is used to show how biomechanical computer modeling can reveal how extinct animal limbs functioned (with a substantial margin of error that can be addressed explicitly in the models). The elephant study is used to show how classical anatomical observation and three- dimensional (3D) imaging have powerful synergy for characterising extant animal morphology , without biomechanical modeling, but also as a first fi step toward such modeling. We focus on how a combination of classical techniques (particularly dissection, osteology, and functional anatomy) and modern techniques (especially imaging and computer modeling) are integrated to reveal how limbs function, and how anatomy is related to behavioral analyses such as biomechanics. We hope that this might inspire other functional biologists, clinicians, or research- ers in other disciplines to see how an integration of anatomical methods can yield exciting insights into animal function or behavior. 1 Structure and Motion Laboratory , Department of Veterinary Basic Sciences, The Royal Veterinary College, University of London, Hatfield, Hertfordshire AL9 7TA, UK, and fi 2 Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany 3.1 Introduction What makes so many animals, living and extinct, so popular and distinct is anatomy; it is what leaps out at a viewer first whether they observe a muse- fi um’s mounted Tyrannosaurus skeleton or an ele- phant placidly browsing on the savannah. Anatomy alone can make an animal fascinating – so many animals are so physically unlike human observers, yet what do these anatomical differences mean for the lives of animals? The behavior of animals can be equally or more stunning- how fast could a Tyrannosaurus move (Coombs 1978; Alexander 1989; Paul 1998; Farlow et al. 2000; Hutchinson and Garcia 2002; Hutchin- son 2004a,b), or how does an elephant manage to momentarily support itself on one leg while ‘running’ quickly (Gambaryan 1974; Alexander et al. 1979; Hutchinson et al. 2003, 2006)? Yet to attain a fundamental understanding of many animal behaviors we must venture beneath their skin surface and analyze the anatomical structures that constrain and enable visible behaviors . An elephant does not manage the aforementioned unipodal feat by sheer willpower or neurological activity alone – muscles, tendons, and bones must provide enough support. Indeed, in the case of an extinct animal, except for fossilized footprints and other tantalizing evidence of behavior, anatomy is