PHILIPPINE BENT-TOED GECKOS OF THE CYRTODACTYLUS AGUSANENSIS COMPLEX: MULTILOCUS PHYLOGENY, MORPHOLOGICAL DIVERSITY, AND DESCRIPTIONS OF THREE NEW SPECIES LUKE J. WELTON 1 ,CAMERON D. SILER 1 ,CHARLES W. LINKEM 1 ,ARVIN C. DIESMOS 2 , AND RAFE M. BROWN 1,3 1 Department of Ecology and Evolutionary Biology, Natural History Museum and Biodiversity Institute, The University of Kansas, Lawrence, KS 66045-7561, USA 2 Herpetology Section, Zoology Division, National Museum of the Philippines, Padre Burgos Avenue, Ermita 1000, Manila, Philippines ABSTRACT: We review the taxonomic status of Philippine bent-toed geckos previously referred to Cyrtodactylus agusanensis. We delineate four evolutionary lineages within the C. agusanensis complex from the southeastern islands of the archipelago and describe three of these lineages as new species. The new species and true C. agusanensis are identified by numerous, nonoverlapping morphological characters and by allopatric ranges on separate islands. Our morphology-based taxonomic conclusions are bolstered by biogeographic evidence and marked interspecific divergence between monophyletic groups defined by mitochondrial and nuclear DNA sequences. To compliment these descriptions and enable future taxonomic work on Philippine Cyrtodactylus, we rediagnose and redescribe C. agusanensis. Because the holotype of C. agusanensis was destroyed in World War II, we designate a neotype for this species and restrict its geographic range to north central Mindanao Island. Our phylogenetic estimate suggests that the C. agusanensis complex originated in Mindanao and spread progressively north, diversifying incrementally with colonization of successive islands in a south-to-north pattern of biogeographic expansion and allopatric speciation. Key words: Cyrtodactylus; Geckos; Gekkonidae; New species; Philippines; Species delimitation PHILIPPINE gekkonids of the genus Cyrto- dactylus include six currently recognized species: C. agusanensis, C. annulatus, C. jambangan, C. philippinicus, C. redimiculus, and C. tautbatorum. Two of these species, C. jambangan and C. tautbatorum, were recently described, having previously been assigned to the ‘‘widespread’’ species C. annulatus (Wel- ton et al., 2009, 2010). Our recent survey of morphological variation in the Philippine members of the genus, supported by phylo- genetic analysis of DNA sequences and new interpretation of biogeographic evidence, has identified multiple highly divergent lineages in the ‘‘widespread’’ species complexes of the archipelago’s bent-toed geckos (Siler et al., 2010; Welton et al., 2010). Taylor (1915, 1922) described C. agusanen- sis on the basis of specimens from Bunawan, northeastern Mindanao Island. Brown and Alcala (1978) further documented the pres- ence of C. agusanensis on the islands of Mindanao and Leyte, and Ross and Lazell (1991) reported C. agusanensis on Dinagat Island on the basis of a single specimen collected by Everett (BMNH 77.10.9.25). At the time of their review, Brown and Alcala (1978) acknowledged the considerable degree of morphological variation in this group but considered these isolated insular populations to be representative of extremes at the ends of a continuous range of intraspecific variation. A recent phylogenetic analysis of the combined data from the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) and the second intron of the nuclear ribosomal protein gene L35 (RPL35) uncovered deeply divergent lineages of C. agusanensis from some islands in its range (Siler et al., 2010). We augmented that dataset with genetic samples of C. agusanensis from near the type locality on Mindanao (Fig. 1) and examined patterns of genetic and morphological varia- tion across the range of C. agusanensis. In this study, we examined morphological characters, meristic and mensural data, and color pattern characters from throughout the known range of C. agusanensis, including new localities from Samar, Leyte, Dinagat, and Mindanao islands. Our effort focused on 3 CORRESPONDENCE: e-mail, rafe@ku.edu Herpetological Monographs, 24, 2010, 55–85 E 2010 by The Herpetologists’ League, Inc. 55