Molecular Systematics and Evolution of Regina and the Thamnophiine Snakes

✍ Scribed by Michael E. Alfaro; Stevan J. Arnold

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 292 KB
• Volume: 21
• Category: Article
• ISSN: 1055-7903
• DOI: 10.1006/mpev.2001.1024

✦ Synopsis

Snakes of the tribe Thamnophiini represent an ecologically important component of the herpetofauna in a range of habitats across North America. Thamnophiines are the best-studied colubrids, yet little is known of their systematic relationships. A molecular phylogenetic study of 32 thamnophiine species using three complete mitochondrial genes (cytochrome b, NADH dehydrogenase subunit 2, and 12S ribosomal DNA) recovered a well-supported phylogeny with three major clades: a garter snake group, a water snake group, and a novel semifossorial group. The historically contentious genus Regina, which contains the crayfish-eating snakes, is polyphyletic. The phylogeographic pattern of Thamnophis is consistent with an hypothesis of at least one invasion of northern North America from Mexico.