a new species of scincid lizard (genus sphenomorphus) - BioOne

68 HERPETOLOGICA [Vol. 66, No. 1Past zoogeographic work has suggested astrong faunal relationship between Palawanand Borneo as a result of a possible landconnection during the last Pleistocene glacialmaximum (Heaney, 1986; Huxley, 1868; butsee Brown and Diesmos, 2009; Brown andGuttman, 2002). Huxley (1868) modified thenorthwestern portion of Wallace’s zoogeographicbarrier, separating the Philippines intotwo zoogeographic zones and placing PalawanIsland as part of the Sunda Shelf/Asian fauna.Brown and Guttman (2002) and McGuire andKiew (2001) provided some of the firstphylogenetic evidence suggesting that someof Palawan’s endemic amphibians and reptilesmay be more closely related to the oceanicportions of the Philippines, to the exclusion ofthe Sunda Shelf. With no clear distinction inthe literature on the affinity of Palawan fauna,it is critical to compare it with the fauna of bothBorneo and the oceanic Philippines.In this paper, we describe a new species oflygosomine skink from Palawan Island, foundduring a collaborative survey between ConservationInternational Philippines and the Universityof Kansas Biodiversity Institute. Weassign this new species to the genus Sphenomorphusbased on the presence of enlargedmedial precloacal scales that overlap lateralprecloacal scales; supradigital scales double ortriple and imbricate; hemipenes bifurcate; lackof undivided transparent scale in lower eyelid;four pentadactyl limbs; and fewer than 30subdigital lamellae on Toe IV (Lim, 1998; Sheaand Greer, 2002; Taylor, 1963). We furtherplace this species in the Sphenomorphusvariegatus Group (Greer and Parker, 1967a),which includes Philippine Group IV (Brownand Alcala, 1980), based on the followingexternal and internal characters: lack of postorbitalbone; supratemporal fenestra very small;no anterior projection of the ectopterygoidprocess; well developed digits and limbs whichoverlap when adpressed; and enlarged nuchalslacking. The Sphenomorphus variegatus Groupis spread throughout Asia and Southeast Asia,consisting of 37 species that are phenotypicallysimilar. We compare the new species to speciesin the S. variegatus Group as well as to speciesin geographic proximity to Palawan Island,Borneo, and the Philippines. We show that thenew species differs from its congeners in thecombination of size at maturity, scale morphology,and coloration.MATERIALS AND METHODSA research team supported by ConservationInternational Philippines and the Universityof Kansas Biodiversity Research Center madecollections of animals in forested areas of Mt.Mantalingahan on Palawan Island during July2007. These researchers used multiple techniquesto collect the animals including captureby hand, pitfall traps, and snap traps. Theyfixed all specimens in 10% buffered formalinto preserve them, and after a few months thespecimens were transferred to 70% ethanol.Senior author CWL determined sex bygonadal inspection and performed measurementsusing Mitutoyo digital calipers to thenearest 0.01 mm.Measurements used are snout–vent length(SVL) measured from the tip of the snout tothe cloacal opening; tail length (TL) measuredfrom the cloacal opening to the tip of the tail;axilla–groin distance (AGD) measured fromthe posterior margin of the forelimb insertionto the anterior margin of the hind limbinsertion; head length (HL) measured fromthe anterior margin of the ear opening to thetip of the snout; head width (HW) measuredat the widest part of the temporal region;snout–forelimb length (SFL) measured fromthe anterior margin of the forelimb insertionto the tip of the snout; internarial distance(IND) measured between the dorsal marginof the two nares; rostrum length (RostL)measured from the anterior margin of the eyeto the tip of the snout; interorbital distance(IOD) width of orbital region at mid orbital;eye diameter (ED) measured at widest point;ear diameter (EarD) measured at widestpoint; forelimb length (FLL) measured frombase of palm to elbow; hind limb length(HLL) measured from knee to ankle.Scales were counted by CWL on the rightside of the body with a dissecting microscope.Scale counts include number of paravertebralscales (PVSR), dorsoventral scales between theparietals and the scales at the cloaca on thedorsal side; number of midbody scale rows(MBSR), scale rows around the middle of thebody; number of subdigital lamellae on Toe IV(SDL); number of supralabials (SL); number of