29th June 2004
Michael P. Taylor
School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth PO1 3QL, UK
Dinosaur diversity is analyzed in terms of the number of valid genera within each major clade, Mesozoic age, country, and year of description. Aves (Archaeopteryx + Neornithes) is excluded. Nomina nuda and nomina dubia are not counted. The results show 451 valid dinosaurian genera at the end of 2001, of which 282 are saurischian (112 sauropodomorphs and 170 theropods, including 93 coelurosaurs) and 169 ornithischian, including 11 pachycephalosaurs, 26 ceratopsians, 60 ornithopods, 12 stegosaurs, and 38 ankylosaurs. Thirty-eight genera arose in the Triassic, 124 in the Jurassic, and 289 in the Cretaceous, including 85 in the Campanian and 47 in the Maastrichtian. The Kimmeridgian was the most productive age, averaging 11.18 new genera per million years. Asia was the most productive continent, home to 149 genera, followed by North America (135), Europe (66), Africa (39), South America (52), Australasia (9), and Antarctica (1). Three countries account for more than half of all dinosaur diversity: the U.S.A (105), China (73), and the Mongolia (53). The rate of naming new dinosaurs has increased hugely in recent years, with more genera named in the last 19 years than in all the preceding 158 years.
This abstract is also available on the SVPCA web-site at http://www.svpca.org/years/2004_leicester/abstracts/svpca-papers_a.htm#abst20