Erroneous quadruped walking depictions in natural history museums

Acknowledgements This work is partly based on the diploma work of Adelinda Csapó (entitled Biomechanical Analysis of Quadruped Walking Depictions, with Emphasis on Natural History Museums and Animal Anatomy Books. Eötvös University, Physical Institute, Department of Biological Physics, Budapest, 2007, in Hungarian). We thank Eleonóra Szűcs of the Hungarian Natural History Museum for picturing many of the HNHM specimens. We are grateful to two anonymous reviewers for their valuable and constructing comments.