title: Dietary innovations spurred the diversification of ruminants during the Caenozoic.
abstract: Global climate shifts and ecological flexibility are two major factors that may affect rates of speciation and extinction across clades. Here, we connect past climate to changes in diet and diversification dynamics of ruminant mammals. Using novel versions of Multi-State Speciation and Extinction models, we explore the most likely scenarios for evolutionary transitions among diets in this clade and ask whether ruminant lineages with different feeding styles (browsing, grazing and mixed feeding) underwent differential rates of diversification concomitant with global temperature change. The best model of trait change had transitions from browsers to grazers via mixed feeding, with appreciable rates of transition to and from grazing and mixed feeding. Diversification rates in mixed-feeder and grazer lineages tracked the palaeotemperature curve, exhibiting higher rates during the Miocene thermal maxima. The origination of facultative mixed diet and grazing states may have triggered two adaptive radiations--one during the Oligocene-Miocene transition and the other during Middle-to-Late Miocene. Our estimate of mixed diets for basal lineages of both bovids and cervids is congruent with fossil evidence, while the reconstruction of browser ancestors for some impoverished clades--Giraffidae and Tragulidae--is not. Our results offer model-based neontological support to previous palaeontological findings and fossil-based hypothesis highlighting the importance of dietary innovations--especially mixed feeding--in the success of ruminants during the Neogene.
authors.affiliation: Departmento de Paleobiología, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas, , Pinar 25, 28006 Madrid, Spain, Department of Biological Sciences, Simon Fraser University, , 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada, IRMACS, Simon Fraser University, , 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada, Departamento de Paleontología, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, , José Antonio Novais 2, Madrid 28040, Spain, Department of Zoology, University of British Columbia, , Vancouver, British Columbia V6T 1Z4, Canada, Department of Biological Sciences, Macquarie University, , Sydney, New South Wales 2109, Australia, Departamento de Cambio Medioambiental, Instituto de Geociencias (UCM, CSIC), , José Antonio Novais 2, Madrid 28040, Spain, Departament de Faunes del Neogen i Quaternari, Institut Català de Paleontologia Miquel Crusafont, Edifici ICP, Universitat Autònoma de Barcelona, , Cerdanyola del Vallès 08193, Spain, Departamento de Ciencias de la Tierra, Facultad de Ciencias, Universidad de Zaragoza, , Pedro Cerbuna 12, Zaragoza 50009, Spain.
authors.forename: Juan L
authors.initials: JL
authors.lastname: Cantalapiedra
authors.forename: Richard G
authors.initials: RG
authors.lastname: Fitzjohn
authors.forename: Tyler S
authors.initials: TS
authors.lastname: Kuhn
authors.forename: Manuel Hernández
authors.initials: MH
authors.lastname: Fernández
authors.forename: Daniel
authors.initials: D
authors.lastname: DeMiguel
authors.forename: Beatriz
authors.initials: B
authors.lastname: Azanza
authors.forename: Jorge
authors.initials: J
authors.lastname: Morales
authors.forename: Arne Ø
authors.initials: AØ
authors.lastname: Mooers
mesh_terms: D000220:Adaptation, Biological / Q000502:physiology*; D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D057231:Climate Change; D004032:Diet / Q000266:history*; D005247:Feeding Behavior / Q000502:physiology; D049690:History, Ancient; D010802:Phylogeny; D012418:Ruminants / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity
keywords: Artiodactyla; diet evolution; diversification; palaeoclimate; phylogenetics; ruminants