title: Assessment of available anatomical characters for linking living mammals to fossil taxa in phylogenetic analyses.
abstract: Analyses of living and fossil taxa are crucial for understanding biodiversity through time. The total evidence method allows living and fossil taxa to be combined in phylogenies, using molecular data for living taxa and morphological data for living and fossil taxa. With this method, substantial overlap of coded anatomical characters among living and fossil taxa is vital for accurately inferring topology. However, although molecular data for living species are widely available, scientists generating morphological data mainly focus on fossils. Therefore, there are fewer coded anatomical characters in living taxa, even in well-studied groups such as mammals. We investigated the number of coded anatomical characters available in phylogenetic matrices for living mammals and how these were phylogenetically distributed across orders. Eleven of 28 mammalian orders have less than 25% species with available characters; this has implications for the accurate placement of fossils, although the issue is less pronounced at higher taxonomic levels. In most orders, species with available characters are randomly distributed across the phylogeny, which may reduce the impact of the problem. We suggest that increased morphological data collection efforts for living taxa are needed to produce accurate total evidence phylogenies.
authors.affiliation: School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland t.guillerme@imperial.ac.uk.
authors.forename: Thomas
authors.identifier: 0000-0003-4325-1275
authors.initials: T
authors.lastname: Guillerme
authors.affiliation: School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
authors.forename: Natalie
authors.identifier: 0000-0003-4919-8655
authors.initials: N
authors.lastname: Cooper
mesh_terms: D000818:Animals; D005580:Fossils; D008322:Mammals / Q000033:anatomy & histology* / Q000145:classification*; D010802:Phylogeny; D013045:Species Specificity
keywords: discrete morphological matrix; extinct; phylogenetic clustering; topology; total evidence method