title: Unexpected Convergent Evolution of Nasal Domes between Pleistocene Bovids and Cretaceous Hadrosaur Dinosaurs.
abstract: The fossil record provides tangible, historical evidence for the mode and operation of evolution across deep time. Striking patterns of convergence are some of the strongest examples of these operations, whereby, over time, similar environmental and/or behavioral pressures precipitate similarity in form and function between disparately related taxa. Here we present fossil evidence for an unexpected convergence between gregarious plant-eating mammals and dinosaurs. Recent excavations of Late Pleistocene deposits on Rusinga Island, Kenya, have uncovered a catastrophic assemblage of the wildebeest-like bovid Rusingoryx atopocranion. Previously known from fragmentary material, these new specimens reveal large, hollow, osseous nasal crests: a craniofacial novelty for mammals that is remarkably comparable to the nasal crests of lambeosaurine hadrosaur dinosaurs. Using adult and juvenile material from this assemblage, as well as computed tomographic imaging, we investigate this convergence from morphological, developmental, functional, and paleoenvironmental perspectives. Our detailed analyses reveal broad parallels between R. atopocranion and basal Lambeosaurinae, suggesting that osseous nasal crests may require a highly specific combination of ontogeny, evolution, and environmental pressures in order to develop.
authors: Department of Biological Sciences, Graduate Program in Ecology and Evolutionary Biology, Ohio University, Athens, OH 45701, USA. Electronic address: haley.d.obrien@gmail.com.
authors: Haley D
authors: HD
authors: O'Brien
authors: Department of Archaeology, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia. Electronic address: j.faith@uq.edu.au.
authors: J Tyler
authors: JT
authors: Faith
authors: Department of Anthropology, University of Minnesota, 395 Humphrey Center, 301 19(th) Avenue S, Minneapolis, MN 55455, USA.
authors: Kirsten E
authors: KE
authors: Jenkins
authors: Department of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798, USA.
authors: Daniel J
authors: DJ
authors: Peppe
authors: Department of Anthropology, Queens College, City University of New York, 314 Powdermaker Hall, 65-30 Kissena Boulevard, Flushing, NY 11367, USA.
authors: Thomas W
authors: TW
authors: Plummer
authors: Center for Archaeological Science, University of Wollongong, Room 268, Building 41, Northfields Avenue, Wollongong, NSW 2522, Australia.
authors: Zenobia L
authors: ZL
authors: Jacobs
authors: Center for Archaeological Science, University of Wollongong, Room 268, Building 41, Northfields Avenue, Wollongong, NSW 2522, Australia.
authors: Bo
authors: B
authors: Li
authors: Department of GeoScience, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
authors: Renaud
authors: R
authors: Joannes-Boyau
authors: School of Earth Sciences, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia.
authors: Gilbert
authors: G
authors: Price
authors: School of Earth Sciences, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia.
authors: Yue-Xing
authors: YX
authors: Feng
authors: Department of Anthropology, Harvard University, Peabody Museum, 11 Divinity Avenue, Cambridge, MA 02138, USA.
authors: Christian A
authors: CA
authors: Tryon
mesh_terms: D000818:Animals; D000866:Antelopes / Q000033:anatomy & histology*; D005075:Biological Evolution; D025061:Dinosaurs / Q000033:anatomy & histology*; D005260:Female; D005580:Fossils / Q000033:anatomy & histology*; D007630:Kenya; D008297:Male; D012886:Skull / Q000033:anatomy & histology*