PROC. BIOL. SOC. WASH. 105(4), 1992, pp. 821-833 A NEW LIZARD OF THE GENUS ARTHROSAURA (TEIIDAE) FROM SOUTHERN VENEZUELA Maureen A. Donnelly, Roy W. McDiarmid, and Charles W. Myers Abstract. —Arthrosaura synaptolepis, new species, is a micro teiid lizard from highland localities (1200-1450 m) on Cerro de la Neblina and Pico Tamacuari in the borderland between Venezuela and Brazil. It differs from all other Ar-throsaura in lacking prefrontal scales and in having two (vs. three) pairs of genials. These diagnostic characters seem to have arisen from fusions of a more primitive set of head plates. Other morphological characters and their distri-butions on the Guayana Highlands suggest that Arthrosaura synaptolepis may be the sister species of A. tyleri. Resumen. —El lagarto Arthrosaura synaptolepis, especie nueva, es un micro-teido de localidades altas (1200-1450 m) en el Cerro de la Neblina y el Pico Tamacuari en la frontera entre Venezuela y Brasil. Se distingue de todas las demas especies de Arthrosaura por carecer de escamas prefrontales y en que tiene dos (en vez de tres) pares de geniales. Estos atributos diagnosticos parecen haberse derivado por fusiones de conjuntos mas primitivos de escamas de la cabeza. Otras caracteristicas morfologicas, y distribucionales incluyendo al-gunos tepuis venezolanos, sugieren que Arthrosaura synaptolepis es la especie hermana de A. tyleri. Recent explorations in the broken high-lands of extreme southern Venezuela re-vealed the existence of many undescribed species in the montane herpetofaunas (McDiarmid & Paolillo 1988, Donnelly & Myers pers. obs.). The present description is of a small lizard discovered at disjunct localities on the Brazilian border during ex-peditions sponsored by the Venezuelan Fundacion para el Desarrollo de las Cien-cias Fisicas, Matematicas y Naturales (FU-DECI). Materials and Methods The three specimens in the type series of the new species are shared among the col-lections of the American Museum of Nat-ural History, New York (AMNH), the Mu-seo Biologia of the Instituto de Zoologia Tropical, Universidad Central de Venezue-la, Caracas (MBUCV), and the National Museum of Natural History, Washington, D.C. (USNM). The specimen to be cata-logued at MBUCV is parenthetically iden-tified by a USNM catalog number at first citation. We also examined the following conge-neric specimens: Arthrosaura kockii. Suri-nam: Brokopondo: Brownsberg, Mazaroni Plateau, 500 m, AMNH 119400-05. Ar-throsaura reticulata. Venezuela: Amazonas: Neblina Base Camp on Rio Mawarinuma, 140 m(00°50'N,66°10'W), AMNH 133664-65, USNM 317874-79. Arthrosaura tyleri. Venezuela: Amazonas: Cerro Duida, 2164 m, AMNH 36643-45 (type series of Pan-todactylus tyleri). Bolivar: Meseta de Jaua, 1750-1 800 m, USNM 31 7880. Arthrosaura versteegii. Surinam: Brokopondo: 65 km (airline) SSE Paramaribo, 80 m, AMNH 108772, 108774. Scale lengths were measured to the near-
BioStor
