Phyllomedusa 9(1):69-73, 2010 © 2010 Departamento de Ciências Biológicas - ESALQ - USP ISSN 1519-1397 SHORT COMMUNI C ATION Hemipenes of the long-tailed rattlesnakes (Serpentes: Viperidae) from Mexico Robert C. Jadin1,2, Jacobo Reyes Velasco3 and Eric N. Smith1 1 Department of Biology and Amphibian and Reptile Diversity Research Center, University of Texas at Arlington, Box 19498, Arlington, Texas 76019, USA. E-mails:
[email protected],
[email protected]. 2 Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, Colorado 80309, USA. 3 Centro Universitario de Ciencias Biologicas y Agropecuarias. Entorno Biotico A.C. Real de Montroy 321, Villa de Alvarez, Colima, México. 28979. E-mail:
[email protected]. Keywords: Serpentes, Crotalinae, Crotalus, hemipenis, morphology. Palavras-chave: Serpentes, Crotalinae, Crotalus, hemipênis, morfologia. Endemic to the foothills of western México, Because of the paucity of specimens and their long-tailed rattlesnakes are a group of three unique morphology, evolutionary relationships poorly known species: the Sinaloan Long-tailed between the long-tailed rattlesnakes and other Rattlesnake, Crotalus stejnegeri Dunn, 1919; the groups have been difficult to establish. Histori Manantlán Long-tailed Rattlesnake, C. lannomi cally, the relationships of long-tailed rattlesnakes Tanner, 1966; and the Guerreran Long-tailed have been considered “uncertain” or incertae Rattlesnake, C. ericsmithi Campbell and Flores- sedis (Gloyd 1940, Meik and Pires-da-Silva Villela, 2008. They received their common name 2009), tentatively associated with C. polystictus from their unique tail length, about 9.7–15.9% of (Brattstrom 1964), or assigned to the C. trise the total length (Campbell and Flores-Villela riatus Group (Klauber 1972).