Welcome to Lizardland, USA! Biodiversity of saurians in the American Southwest and zeroing in on an Arizona-New Mexico hotspot

Jones, Lawrence L.C.

Southwest Zoologists' League

gilaman@comcast.net

Over 80% of the lizard diversity in the United States occurs in the American Southwest, from California to Texas, west of the Pecos. Most of the diversity occurs near the borderlands with México. Within that large expanse, I will be focusing in on a region that may be referred to as the Madrean Archipelago and Lowlands (more-or-less the Cochise Filter-Barrier) of southwestern Arizona and adjacent New Mexico This region is well-known to herpetologists as a hotbed of lizard diversity, having the largest number of sympatric species north of México. This region is a mixing point of biotic communities. It is at the junction of the Sonoran and Chihuahuan deserts in the lowlands and the Petran and Madrean montane woodlands and forests at higher elevations. The diversity of the region is due to a number of factors, including connectivity with México, broad elevational gradients, biogeographic dispersal routes, a long growing season, and a dual rainy season. Rather than getting bogged down in the complexities and nuances of biogeography (especially during an icebreaker!), I would rather share some eye candy of the stunning array of lizards to be found within striking distance of Rodeo, New Mexico.