@article{acdfba3a9f1c46e090a2b5d5529a2839,
title = "Intraspecific variation and directional casque asymmetry in adult southern cassowaries (Casuarius casuarius)",
abstract = "The cranial casques of modern cassowaries (Casuarius) have long intrigued researchers; however, in-depth studies regarding their morphological variation are scarce. Through visual inspection, it has been recognized that casque variability exists between conspecifics. Understanding casque variation has both evolutionary and ecological importance. Although hypothesized to be targeted by selection, intraspecific casque variation has not been quantified previously. Through a large sample of C. casuarius (n = 103), we compared casque shape (lateral and rostral views) between sexes and between individuals from non-overlapping geographical regions using two-dimensional (2D) geometric morphometrics. We found no statistically significant differences between the casque shape of females and males and few substantial shape differences between individuals from different geographic areas. Much of the intraspecific variation within C. casuarius is due to casque asymmetries (77.5% rightward deviating, 20.7% leftward deviating, and 1.8% non-deviating from the midline; n = 111), which explain the high variability of southern cassowary casque shape, particularly from the rostral aspect. Finally, we discuss how our non-significant findings implicate social selection theory, and we identify the benefits of quantifying such variation for further elucidating casque function(s) and the social biology of cassowaries.",
keywords = "cranial structure, geometric morphometrics, paleognathous birds, phenotypic variation, shape analysis, social selection, theropod, visual display",
author = "Green, {Todd L.} and Kay, {David Ian} and Gignac, {Paul M.}",
note = "Funding Information: Funding for this study was provided by the following organizations: National Science Foundation (1450850, 1457180, 1725925, &; to P. M. G.), OSU-CHS, Western Interior Paleontological Society (Karl Hirsch Memorial Grants; to T. L. G.), The Company of Biologists and sponsoring journal, Experimental Biology (Visiting Fellowship, JEBTF1903122; to T. L. G.), and American Association for Anatomy (Visiting Scholarship; to T.L.G.). For specimen access and/or donation the authors thank: AMNH (Paul Sweet, Joel Cracraft, Thomas Trombone, Bentley Bird), BVZ (M. David Quavillon, Michelle Ferguson, Ellen Dreyer, Michelle Smurl), CCP (R. Glenn Hood, Scott Snedeker), DMNS (Garth Spellman, Jeff Stephenson, Andrew Doll), MOO (Jay Villemarette, Michelle Hayer), MV (Ricky-Lee Erickson, Kylea Clarke), NHMUK (Hein Van Grouw, Mark Adams, Joanne Cooper, Judith White, Paul Kitching, Pete Key, Claire Walsh), QM (Heather Janetzki, Kristen Spring, Alison Douglas), SCZ (Scott Newland, Heather Arens, Phillip Horvey), UNE (Karl Vernes). Range data for Casuarius were provided by BirdLife International (Mark Balman). Information regarding native Australian cassowary habitat and photograph usage was provided through the kind help of Queensland Parks and Wildlife Service and Partnerships (John De Campo), Wet Tropics Management Authority (Terry Carmichael), and Community for Coastal and Cassowary Conservation (Peter Rowles). We appreciate μCT imaging assistance from: AMNH (Morgan Hill, Andrew Smith) and MICRO (Manon Wilson). For additional assistance and discussions, the authors extend gratitude to Haley O'Brien, Akinobu Watanabe, Jennifer Campbell-Smith, Nicholas Mahler, Holly Ballard, Jennifer Volberding, Andrew Farke, and Mark Norell. Lastly, we extend a special thank you to the editors and anonymous reviewers for their time and effort to provide suggestions that improved the quality of this article. Funding Information: Funding for this study was provided by the following organizations: National Science Foundation (1450850, 1457180, 1725925, &; to P. M. G.), OSU‐CHS, Western Interior Paleontological Society (Karl Hirsch Memorial Grants; to T. L. G.), The Company of Biologists and sponsoring journal, Experimental Biology (Visiting Fellowship, JEBTF1903122; to T. L. G.), and American Association for Anatomy (Visiting Scholarship; to T.L.G.). For specimen access and/or donation the authors thank: AMNH (Paul Sweet, Joel Cracraft, Thomas Trombone, Bentley Bird), BVZ (M. David Quavillon, Michelle Ferguson, Ellen Dreyer, Michelle Smurl), CCP (R. Glenn Hood, Scott Snedeker), DMNS (Garth Spellman, Jeff Stephenson, Andrew Doll), MOO (Jay Villemarette, Michelle Hayer), MV (Ricky‐Lee Erickson, Kylea Clarke), NHMUK (Hein Van Grouw, Mark Adams, Joanne Cooper, Judith White, Paul Kitching, Pete Key, Claire Walsh), QM (Heather Janetzki, Kristen Spring, Alison Douglas), SCZ (Scott Newland, Heather Arens, Phillip Horvey), UNE (Karl Vernes). Range data for were provided by BirdLife International (Mark Balman). Information regarding native Australian cassowary habitat and photograph usage was provided through the kind help of Queensland Parks and Wildlife Service and Partnerships (John De Campo), Wet Tropics Management Authority (Terry Carmichael), and Community for Coastal and Cassowary Conservation (Peter Rowles). We appreciate μCT imaging assistance from: AMNH (Morgan Hill, Andrew Smith) and MICRO (Manon Wilson). For additional assistance and discussions, the authors extend gratitude to Haley O'Brien, Akinobu Watanabe, Jennifer Campbell‐Smith, Nicholas Mahler, Holly Ballard, Jennifer Volberding, Andrew Farke, and Mark Norell. Lastly, we extend a special thank you to the editors and anonymous reviewers for their time and effort to provide suggestions that improved the quality of this article. Casuarius Publisher Copyright: {\textcopyright} 2022 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.",
year = "2022",
month = oct,
doi = "10.1111/joa.13733",
language = "English",
volume = "241",
pages = "951--965",
journal = "Journal of Anatomy",
issn = "0021-8782",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "4",
}