bioRxiv preprint doi: https://doi.org/10.1101/607796; this version posted April 13, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Phylogenetic and Spatial Distribution of Evolutionary Isolation and Threat in Turtles and 2 Crocodilians (Non-Avian Archosauromorphs) 3 Timothy J. Colston1,4†*, Pallavi Kulkarni2, Walter Jetz3, R. Alexander Pyron1† 4 Affiliations 5 1Dept. oF Biological Sciences, The George Washington University, Washington, DC USA 20052 6 2Herndon High School, Herndon, VA USA 20170 7 3Dept. oF Ecology & Evolutionary Biology, Yale University, NeW Haven, CT USA 06511 8 4Current AFFiliation: Department oF Biological Science, Florida State University, Tallahassee, FL 9 USA 32304 10 *Correspondence to:
[email protected] 11 †These authors contributed equally to this manuscript 12 Abstract 13 The origin of turtles and crocodiles and their easily recognized body forms dates to the Triassic. 14 Despite their long-term success, extant species diversity is low, and endangerment is extremely 15 high compared to other terrestrial vertebrate groups, With ~ 65% oF ~25 crocodilian and ~360 16 turtle species noW threatened by exploitation and habitat loss. Here, We combine available 17 molecular and morphological evidence With machine learning algorithms to present a 18 phylogenetically-informed, comprehensive assessment oF diversiFication, threat status, and 19 evolutionary distinctiveness oF all extant species. In contrast to other terrestrial vertebrates and 20 their oWn diversity in the Fossil record, extant turtles and crocodilians have not experienced any 21 mass extinctions or shiFts in diversiFication rate, or any signiFicant jumps in rates oF body-size 22 evolution over time.