13 African Journal of Herpetology, 2006 55(1): 13-22. T he leaf-toed geckos of equatorial Africa and the Seychelles were long included in the genus Diplodactylus, but following the restriction of this genus to Australian taxa (Underwood 1954) they were transferred to the nearly cosmopolitan Phyllodactylus (see also Loveridge 1959). For almost three decades most authors assigned these geckos to this genus (but see Eisentraut 1963; Perret 1963) until Kluge (1983) established the genus Urocotyledon to accommodate the four species currently recognised, U. inexpectata (Stejneger 1893), U. wolterstorffi (Tornier 1900), U. palmata (Mocquard 1902) and U. weileri (Müller 1909), all of which share the derived features of loss of the second ceratobranchial arch and presence of a subcaudal scansorial pad. Subsequent authors have accepted Urocotyledon as a valid genus (Broadley & Howell 1991; Bauer et al. 1997; Nussbaum et al. 1998; Rösler 2000) and attempts to place the genus phylogenetically have considered it part of a broad radiation of Afro-Malagasy taxa (Bauer 1990; Kluge & Nussbaum 1995; Rittenhouse et al. 2000) but there is little sup- port for particular intergeneric relationships. Urocotyledon is of particular biogeographic interest because of its strange distribution, with two species in Cameroon (U. palmata and U. weileri), one in Tanzania (U. wolterstorffi), and another in the Seychelles (U. inexpectata) — a pattern shared by no other reptile genus. However, its species are rarely encountered and remain among the most poorly known of all geckos. Despite the few constituent taxa, species com- position of Urocotyledon has been somewhat Herpetological Association of Africa Original article A new species of Prehensile-tailed Gecko, Urocotyledon (Squamata: Gekkonidae), from the Udzungwa Mountains, Tanzania AARON M. BAUER 1 AND MICHELE MENEGON 2 1 Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, Pennsylvania 19085, USA; aaron.bauer@villanova.edu 2 Sezione di Zoologia dei Vertebrati, Museo Tridentino di Scienze Naturali, Via Calepina 14, I-38100 Trento, Italy; menegon@mtsn.tn.it Abstract.—A new species of prehensile-tailed gecko of the genus Urocotyledon is described from the dry western slopes of the Udzungwa Mountains in Tanzania. The species is most similar to its west African congeners, differing significantly from U. wolterstorffi of the Usambara and Uluguru Mountains of Tanzania in scalation, tail shape, and coloration. The new species differs from all other members of the genus in its reduced number of subdigital lamellae. This is the first putatively endemic species of reptile to be identified from the dry forest of the western slopes of the Udzungwa Mountains. Its pres- ence suggests that more survey effort should be made in drier areas of the Eastern Arc Mountains. Key words.—Urocotyledon, Gekkonidae, Udzungwa Mountains, Tanzania, dry forest, description.