Title | Molecular systematics and evolution of Regina and the Thamnophiine snakes |
Publication Type | Journal Article |
Year of Publication | 2001 |
Authors | Alfaro, ME, Arnold, SJ |
Journal | Molecular Phylogenetics and Evolution |
Volume | 21 |
Pagination | 408-423 |
Keywords | 12s ribosomal-rna phylogenetic analysis maximum-likelihood strepsiptera problem secondary structure dna-sequence substitution incongruence saturation characters |
Abstract | 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. (C) 2001 Elsevier Science. |