Members of the Crotalus durissus species complex are widely distributed from Mexico to Argentina in areas with mainly seasonally dry tropical deciduous forest. Although four species (C. culminatus, C. durissus, C. simus and C. tzabcan) are currently recognized, species limits remain to be tested. Previous genetic studies suggest that C. durissus and C. simus may be paraphyletic and that at least one cryptic species may be present. We analyzed 2596 bp of DNA sequence data from three mitochondrial and one nuclear gene to infer phylogenetic relationships in the Neotropical rattlesnakes. We also examined museum and wild specimens as well as captive animals to analyze morphological characters. Our results suggest that the current taxonomy of the Crotalus durissus species complex does not reflect evolutionary history. We found strong support for five independent lineages within Crotalus simus (sensu lato), with genetic and morphological evidence for three previously recognized taxa and two new species, as well as three major lineages within C. durissus that each represent species hypothesis to be tested with additional evidence. We also found support to retain C. totonacus in the Crotalus molossus species complex. We suggest conservative taxonomic changes to the complex and related species, but more evidence is needed (e.g., morphology, ecology and venom composition) to clarify relationships among species.

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Two adult female specimens of the lizard Sceloporus torquatus kyphosis from the municipality of Aguascalientes, Mexico are reported herein. specimen with the deformity in the cervical area and specimen B in the thoracic area.

Se registra la presencia de Crotalus aquilus en el bosque de encino, en la Sierra El Laurel, municipios de Huanusco, Jalpa y Nochistlán de Mejía, Zacatecas. Estos ejemplares representan los primeros registros para Zacatecas y amplían la distribución de C. aquilus a través de la Sierra El Laurel hacia la parte de Zacatecas.

Abstract:We report an adult male specimen of the snake Pantherophis emoryi from xerophytic scrub habitat in the Municipality of Real de Asientos, Aguascalientes, México. This specimen represents the first state record of P. emoryi from Aguascalientes and extends the known distribution of the species 107 km in a straight line west-northwest from the nearest previous record. Our specimen was found in habitat that is under heavy agricultural pressure, and recently, threatened by mining. This may indicate that other Chihuahuan Desert taxa may be found in this area. crop and livestock production, and also threatened by mining. This and other recent herpetofaunal findings in the arid zone of Aguascalientes suggest that additional species typical of the Chihuahuan Desert may be found in this area. ACKNOWLEDGEMENTSWe thank J. Jesus Sigala Rodríguez for comments on previous draft of this note and for information provided.