A Revision of the Pachydactylus Serval and P. Weberi Groups (Reptilia: Gekkota: Gekkonidae) of Southern Africa, with the Description of Eight New Species
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/229042874 A revision of the Pachydactylus serval and P. weberi groups (Reptilia: Gekkota: Gekkonidae) of Southern Africa, with the description of eight new species Article · January 2006 CITATIONS READS 18 419 3 authors: A. M. Bauer Trip Lamb Villanova University East Carolina University 661 PUBLICATIONS 10,121 CITATIONS 82 PUBLICATIONS 4,569 CITATIONS SEE PROFILE SEE PROFILE William R Branch Nelson Mandela University 265 PUBLICATIONS 4,667 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Journal of Animal Diversity (http://jad.lu.ac.ir) View project Trachylepis systematics View project All content following this page was uploaded by Trip Lamb on 03 September 2014. The user has requested enhancement of the downloaded file. PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES Fourth Series Volume 57, No. 23, pp. 595–709, 124 figs., Appendix (9 tables). September 15, 2006 A Revision of the Pachydactylus serval and P. weberi Groups (Reptilia: Gekkota: Gekkonidae) of Southern Africa, with the Description of Eight New Species Aaron M. Bauer1,4,Trip Lamb2, and William R. Branch3 1Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, Pennsylvania 19085, USA; Email: [email protected]; 2Department of Biology, East Carolina University, Greenville, North Carolina 27858, USA; Email: [email protected]; 3Port Elizabeth Museum, P.O. Box 13147, Humewood 6013, Republic of South Africa; Email: [email protected] The Pachydactylus serval and weberi groups constitute a clade of small to moderate sized (typically 40–50 mm SVL), mostly rupicolous geckos that are distributed wide- ly in western South Africa and Namibia, with scattered populations in eastern Namibia and adjacent northwestern Botswana. The taxonomic status of many of the described members of these groups has long been unresolved, and numerous subtly divergent populations have been identified since the last revisionary work was under- taken. Examination of more than 1800 specimens referable to these species groups permits recognition of at least 21 species, clearly divisible into serval and weberi sub- clades. Within these clades, most species are highly morphologically conservative, although there are diagnostic differences in a number of characters, most notably juvenile color pattern. The species boundaries so revealed are supported by phyloge- netic evidence from the cytochrome b mitochondrial gene. The validity of the current- ly recognized species in the P. serval/weberi clade (P. serval, P. weberi, P. fasciatus, P. tsodiloensis, P. waterbergensis) is confirmed, and the taxa P. purcelli, P. acuminatus, P. werneri are elevated from synonymy or subspecific rank to full species. Pachydactylus robertsi, recently removed from the synonymy of P. scutatus, and P. kobosensis are confirmed as valid members of the P. weberi group. Pachydactylus sansteynae, origi- nally described as a subspecies of P. serval, is a valid species but is not a member of P. serval/weberi clade. Pachydactylus montanus is a senior subjective synonym of P. onscepensis and is raised from the synonymy of P. serval. A genetically diverse taxon, P. montanus may include more than one biological species. In addition, eight new species are described and the existence of two additional taxa, each currently known from limited material, is noted. The areas of greatest diversity for the clade as a whole are along the lower Orange River and in southern Namibia. Both the Richtersveld/ Hunsberg region in the west and the Karasberge in the east harbor at least five species in the P. serval/weberi clade. The evolutionary history of the group is proba- bly associated with the fragmentation of rocky substrates and the historical isolation of some regions by changing paleopositions of the drainage of the Orange River. Distribution patterns of geckos in this clade are coincident with those of cordylids and scorpions and together, these groups — all of which have explicit hypotheses of relationships — provide a possible basis for a fine-scaled biogeographic analysis of western portions of the southern African subcontinent. KEY WORDS: Gekkonidae, Pachydactylus, systematics, species description, Namibia, South Africa, molecular phylogeny, biogeography 4 Research Associate, Department of Herpetology, California Academy of Sciences. 595 596 PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES Fourth Series, Volume 57, No. 23 The monophyly of the southern African Pachydactylus group of geckos has long been recog- nized on the basis of the unique hyperphalangic condition of digit I of the manus and pes (Haacke 1968, 1976; Russell 1972; Joger 1985; Bauer 1990; Kluge and Nussbaum 1995). Monophyly of Pachydactylus itself, however, has been questioned on the grounds that: 1) it is made paraphyletic by its inclusion of the highly specialized taxa Colopus, Palmatogecko (including Kaokogecko) and Chondrodactylus, and 2) the precloacal pore-bearing P. tuberculosus and P. tetensis are basal to the remainder of Pachydactylus plus Rhoptropus (e.g., Joger 1985). The latter hypothesis has been rejected on the grounds of morphological, allozyme, and molecular evidence that supports Rhoptropus as the sister group of Pachydactylus sensu lato (Bauer and Good 1996; Lamb and Bauer 2001, 2002). The paraphyly of Pachydactylus relative to the burrowing genera Colopus, Palmato- gecko, and Chondrodactylus was raised as a possibility by Haacke (1976) and explicitly proposed by Joger (1985). Bauer (1990) and Kluge and Nussbaum (1995) accepted Joger’s interpretation as likely, but their own analyses were at the generic level and thus incapable of corroborating generic paraphyly. Recently, however, a phylogenetic analysis of the southern African Pachydactylus group based on mitochondrial and nuclear DNA sequence data (Bauer and Lamb 2005; Lamb and Bauer 2006) has confirmed Joger’s (1985) hypothesis and demonstrated that each of the burrowing gecko genera evolved independently within Pachydactylus. Among the taxonomic consequences of this work has been the allocation of several species of Pachydactylus to the genera Elasmodactylus, Chondrodactylus and Colopus. Nonetheless, Pachydactylus remains the most speciose genus of southern African geckos. Within Pachydactylus sensu stricto, a number of species groups have been recognized on the basis of overall morphological similarity (e.g., McLachlan and Spence 1966; Broadley 1977). Several of these groups have been reexamined using combinations of morphological, allozyme, and DNA sequence data, resulting in both the confirmation of the monophyly of these groups and in the recognition of additional species level taxa. In particular, the P. rugosus group, P. capensis group, P. scutatus group, and P. namaquensis group have been the subject of recent reviews and revisions (Branch et al. 1996; Lamb and Bauer 2000; Bauer and Lamb 2002; Bauer et al. 2002; Broadley 2003). The monophyly of all of these groups has been corroborated in two recent molecular phylo- genies (Bauer and Lamb 2005; Lamb and Bauer 2006). In these, the most complete phylogenetic analyses to date, the Pachydactylus serval/weberi group (McLachlan and Spence 1966) was revealed to be the sister group of the P. capensis group. The serval/weberi group has been among the most problematic components of Pachydactylus and, until now, species boundaries within this group have defied resolution. Members of the group are relatively small (typically < 50 mm SVL), primarily rock-dwelling geckos with relatively flat- tened bodies, distributed from the Western Cape Province of South Africa through northern Namibia. Despite being widespread and locally abundant, these geckos have had a long history of taxonomic confusion, stemming in part from the poor sampling that characterized most southern African geckos until the middle third of the 20th century, when V. F. FitzSimons of the Transvaal Museum made important collections throughout much of the arid zones of southwestern Africa. At present only two species, P. weberi Roux, 1907 and P. serval Werner, 1910, are recognized by most authors (e.g., Branch 1998; Griffin 2003), and the non-nominate subspecies P. serval purcelli, P. s. onscepensis, P. weberi acuminatus, and P. w. werneri are sometimes regarded as valid (e.g., Kluge 2001). Pachydactylus sansteynae (formerly sansteyni, see Michels and Bauer 2004) was initially described as a subspecies of P. serval (Steyn and Mitchell 1967) but has long been recognized as specifically distinct (Branch 1988). Most recently, P. robertsi, formerly regarded as a subspecies of P. scutatus, has been demonstrated to be closely allied to the P. weberi complex (Bauer et al. 2002). BAUER ET AL.: REVISION OF PACHYDACTYLUS SERVAL AND P. WEBERI GECKOS 597 HISTORICAL RESUMÉ OF THE P. SERVAL AND P. WEBERI GROUPS TO 1943.— Prior to the major revisionary works of FitzSimons (1943) and Loveridge (1947), a great deal of taxonomic confusion existed with respect to various members of the P. serval and P. weberi groups and other small-bod- ied Pachydactylus (sensu Lamb and Bauer 2002). The first specimens referable to the weberi group were reported by Peters (1867), who identified two specimens (ZMB 5711) from Neu Barmen (now Gross Barmen, Namibia) as P. capensis. One of these was subsequently identified as P. formosus by Sternfeld (1911a) and was only much later (Loveridge 1947; Mertens 1955) correctly identified