title: Mass survival of birds across the Cretaceous-Tertiary boundary: molecular evidence.
abstract: The extent of terrestrial vertebrate extinctions at the end of the Cretaceous is poorly understood, and estimates have ranged from a mass extinction to limited extinctions of specific groups. Molecular and paleontological data demonstrate that modern bird orders started diverging in the Early Cretaceous; at least 22 avian lineages of modern birds cross the Cretaceous-Tertiary boundary. Data for several other terrestrial vertebrate groups indicate a similar pattern of survival and, taken together, favor incremental changes during a Cretaceous diversification of birds and mammals rather than an explosive radiation in the Early Tertiary.
authors.affiliation: School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand. alan.cooper@bioanth.ox.ac.uk
authors.forename: A
authors.initials: A
authors.lastname: Cooper
authors.forename: D
authors.initials: D
authors.lastname: Penny
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D001717:Birds / Q000235:genetics; D019143:Evolution, Molecular; D005580:Fossils; D005796:Genes; D016258:Genes, mos; D008322:Mammals / Q000235:genetics; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics
chemical_list: D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S