1. Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02139, USA
2. Departamento de Clinica, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica, 1300-345, Lisboa, Portugal
3. Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, UK
4. Institute of Zoology and Evolutionary Research, Friedrich-Schiller-University Jena, Erbertstr. 1, Jena, 07743, Germany
5. Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, The Royal Veterinary College, Hawkshead Lane, Hatfield, AL9 7TA, UK