Revista Mexicana de Biodiversidad 84: 485-498, 2013 Revista Mexicana de Biodiversidad 84: 485-498, 2013 DOI: 10.7550/rmb.35733 DOI: 10.7550/rmb.35733485 A new species of Xenosaurus (Squamata: Xenosauridae) from the Sierra Gorda Biosphere Reserve of Querétaro, Mexico Una nueva especie de Xenosaurus (Squamata: Xenosauridae) de la Reserva de la Biosfera Sierra Gorda de Querétaro, México Adrián Nieto-Montes de Oca1 , Uri O. García-Vázquez1, J. Jaime Zúñiga-Vega3 and Walter Schmidt-Ballardo2 1Laboratorio de Herpetología, Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México. Circuito exterior s/n, Ciudad Universitaria, 04510 México, D. F., México. 2Museo de Zoología “Alfonso L. Herrera”, Facultad de Ciencias, Universidad Nacional Autónoma de México. Circuito exterior s/n, Ciudad Universitaria, 04510 México, D. F., México. 3Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México. Circuito exterior s/n, Ciudad Universitaria, 04510 México, D. F., México.
[email protected] Abstract. A new species of Xenosaurus from the Sierra Gorda Biosphere Reserve of northeastern Querétaro, Mexico, is described. The new species differs from all of the other described species of the genus by having usually 2 postrostral scales on each side of the midline (in 84.6% of the specimens, n= 26); largest supraoculars that are not, or only slightly, wider than long; postorbital and zygomatic ridges that are widely separated from each other by an intervening row of scales; labiomental rows that usually extend posteriorly_ from the second or third chinshield (in 92.3% of the specimens, n= 26); 23-26 lamellae under the fourth toe (x= 24.3, n= 25); a venter that is immaculate or with only diffuse, scattered dark specks on the sides, and a postorbital region rounded, lacking a canthus temporalis demarcated by enlarged or well-defined scales.