Systematics and biogeography of the widespread Neotropical gekkonid genus Thecadactylus (Squamata), with the description of a new cryptic species Bergmann, Philip J. Russell, Anthony P. Zoological Journal of the Linnean Society 2007 2007-03-31 149 3 339 370   DESCRIPTION OF   THECADACTYLUSSOLIMOENSIS   SP. NOV.  Synonymy: See Russell & Bauer (2002a)for complete list.  Material examined:  Holotype: QCAZ-6691 (= OMNH- 36431). Male, collected by L. J. Vittin 1994 from the type locality of Reserva Faunistica Cuyabeno ( Estacion Biologia da Universidad Catolica), Sucumbios, Ecuador. Description ( Fig. 7A): 116 mmSVL, 76 mmTL, 29 mmHL, 24 mmHW, 6 mm IND; regenerated tail broader than more proximal stump and relatively unpatterned; 4 nasal granules, dorsalmost enlarged; internasals with reduced contact medially; 11 supralabials, 6 anterior to the eye; 10 infralabials; rostral partly divided; 11 spinose supraciliaries; postmetals stubby; 3 post-postmetals, medial one enlarged; 9 post-infralabials; dorsal forearm and ventral neck scales granular; hindlimb web and tail base scales imbricate; 1 single-apexed, pointy cloacal spur; cloacal sacs present; total manual lamellae on digits I, IVand V, 15, 21 and 19, respectively; total pedal lamellae on digits I, IVand V, 18, 22, 20, respectively; scansors on manual and pedal digits IV, 12 and 13, respectively; subdigital sulcus divides all lamellae on manual digit II, but only some on digit I; lateral stripe absent; dorsal colour and pattern light, unmottled, consisting of 5 diamonds; 7 paravertebral pairs of spots, of varying definition, some interconnected across the midline; nuchal spot absent; postocular stripes project posterodorsally, but do not connect middorsally; dark caudal blotches present; 13 teeth occluded by rostral; anterolateral process of parietal swept back; otic capsule anterolateral to occipital complex; 26 presacral vertebrae, 3 cervical vertebrae without ribs; 22 ribs, 2 anterior to medial level of clavicles, 6 shortened; cloacal bones absent; paraphalanges not visible in radiographs.   Figure 7.Photographs of the holotype of  Thecadactylus solimoensis[QCAZ-6691 (= OMNH-36431)] (A), and the neotype of  T. rapicauda(RMNH-16267) (B).   Paratypes: All paratypeswere collected by L. J. Vitt in 1994 from the type locality, but from Neotropic Turis, instead of Estacion Biologia. Five paratypesare defined: OMNH-36427: male, original tail; OMNH- 36428: female, original tail; OMNH-36429: male, regenerated tail; OMNH-36430: male, regenerated tail; and OMNH-36433: female, regenerated tail.  Referred specimens: All those listed in Appendix 1 that originate from Bolivia, Peruand Ecuador. Also, those from the Brazilian states of Amazonas and Rondonia. Tentatively, the single specimen from the southern Colombian state of Caqueta is also referred.  Variation: Presented only for characters that do not span the entire range for  Thecadactylus. 2–5 nasal granules; 8–14 supralabials, 4–7 anterior to the eye; 8–12 infralabials; rostral never fully divided; up to 12 spinose supraciliaries; 2–7 post-postmentals; 4–11 post-infralabials; 1–3 cloacal spurs; total manual lamellae on digits I, IV and V, 13–20, 17–25, 16–24, respectively; total pedal lamellae on digits I, IV and V, 14–21, 19–25, 18–23, respectively; scansors on manual and pedal digits IV, 9–14 and 10–14, respectively; 0–7 dorsal diamonds; 0–8 paravertebral spots; 0–5 dark caudal blotches; 0–10 caudal bands; 11–15 teeth occluded by rostral; 26–27 presacral vertebrae, 2–3 cervicals without ribs; 21–24 pairs of ribs, 0–3 anterior to medial level of clavicles, 5–6 shortened. Although both species of Thecadacytlusare highly variable in general,  T. solimoensisdisplays less variability than does  T. rapicauda. This is especially true in terms of maximal SVL (  T. solimoensisspecimens are relatively large) and in terms of pattern (  T. solimoensisspecimens tend to have a dorsally directed postocular stripe and a dorsal diamond pattern, see below).   Table 4.Tests of equality of means for residual morphometric variables between  Thecadactylus rapicaudaand  T. solimoensis. Included are the test used, the test statistic, associated degrees of freedom and probability. Significant probabilities are in bold type    Variable Test d.f.  t/ U  P  LHL  t 154 0.9533 0.3419  LHW  U 1 2319 0.7506  LHD  t 154 1.0321 0.3036  LIND  t 153 −3.7487  0.0003  LEND  t 154 2.9907  0.0032  LIOD  t 154 −2.7614  0.0065  LOD  U 1 2756  0.0338  LEED  t 154 −2.6042  0.0101  LAGD  U 1 1458  0.0012  LFLL1  t 154 2.5851  0.0107  LFLL2  t 154 1.2533 0.2120  LHLL1  U 1 2624 0.1148  LHLL2  t 154 3.2435  0.0014  LHLL3A  t 154 −3.4762  0.0007  L4TL  U 1 2239 0.9901  L4TW  U 1 1597  0.0077  L1TL  U 1 1564  0.0051  L1TW  t 154 −1.1509 0.2516  LWB  U 1 1904 0.1629  Diagnosis:  Thecadactylus solimoensisinvariably possesses strongly dilated subdigital pads, well-developed subdigital sulci that house the claws and divide the lamellae into two series, and interdigital webs, uniting it with  T. rapicaudawithin the genus.  T. solimoensisalso possesses morphological, morphometric and molecular autapomorphies that distinguish it from  T. rapicauda. Morphological and morphometric divergence is less pronounced than molecular divergence, which includes sequence divergences of 23.0–26.9% between the two species ( Kronauer et al., 2005). Morphological characters that diagnose  T. solimoensisare never fixed, but are possessed by the majority of specimens. This is unsurprising for a cryptic species, and similar characters have been used as diagnostic by other authors ( Branch, Bauer & Good, 1996; Wiens & Penkrot, 2002). Four morphological characters are here denoted as diagnostic. The strongest of these is that 78% of specimens examined have a dorsally directed postocular stripe, compared with <0.01% of specimens of  T. rapicauda. Seventy-seven per cent of those specimens examined have a dorsal diamond pattern (39% of  T. rapicauda), and 69% possess stubby postmental scales (53% of  T. rapicauda). Finally, 65% of specimens assigned to  T. solimoensishave granular scales on the gular region (25% in  T. rapicauda). All morphometric characters examined have a high degree of range overlap between  T. solimoensisand  T. rapicauda. However, significant differences occur in some, when size-removed (residual data set) species means are compared using two-sample t-tests or Mann–Whitney U-tests, as appropriate ( Table 4). Mean values for  T. solimoensisare significantly greater for internasal distance, interorbital distance, ear–eye distance, axilla–groin distance, metatarsus length, fourth toe width and first toe length than for  T. rapicauda. Means are significantly less for eye– naris distance, orbital diameter, upper arm length and crus length than for  T. rapicauda( Table 4). Cytochrome bsequences between the two species are highly distinct ( Kronauer et al., 2005; see above). As molecular evidence provides very strong support for the recognition of a second species ( Seberg, 2004) and broad geographical samplings of numerous specimens for each species were included, diagnostic molecular characters are detailed ( Table 5). A smaller cyt bsample size would tend to inflate these differences and negate the use of this approach. Of 584 bp sequenced, 26 are fixed and exclusive to  T. solimoensis. A further 9 bp are fixed and almost exclusive to  T. solimoensisin that only a single specimen sequenced of  T. rapicaudashares the same nucleotide. Within the sequenced fragment, a highly diagnostic region, located between nucleotide positions 489 and 532, contains 12 of the 35 fixed sites, ten of which are exclusive ( Table 5).   Table 5.Nucleotide autapomorphies for  Thecadactylus solimoensis, including position in the sequenced fragment ( Kronauer et al., 2005), position relative to the mitochondrial genome of  Eumeces egregius(Scincidae)( Kumazawa & Nishida, 1999), character state at that position and homologous character state for  T. rapicauda. Asterisks denote characters that are not fully exclusive to  T. solimoensis(see text)    Fragment Genome NTP NTP Fragment Genome NTP NTP  position position  T. s.  T. r. position position  T. s.  T. r.  31 14 574 A C 481 15 024 AG* CT  63 14 606 C* AG 489 15 032 T C  95 14 638 G* T 490 15 033 A CT  97 14 640 T AG 493 15 036 A CT  160 14 703 C AG 494 15 037 T* C  223 14 766 C AGT 499 15 042 T* AC  235 14 778 A C 500 15 043 A C  283 14 826 T* AC 509 15 052 C A  311 14 854 T C 517 15 060 C AG  314 14 857 T C 520 15 063 CG AT  327 14 870 A C 523 15 066 C AG  328 14 871 C* A 529 15 072 A CT  334 14 877 A CT 532 15 075 AG CT  364 14 907 A CT 550 15 093 AG CT  415 14 958 A* CGT 559 15 102 C AG  454 14 997 CT AG 570 15 113 C G  457 15 000 AG* CT 574 15 117 A CT  475 15 018 G A  Distribution:  T. solimoensisoccurs throughout Ecuador, Peruand Bolivia, only east of the Andes, in Brazilian Amazonas and Rondonia, and in southern Colombia( Fig. 1). The western and southern extent of its range is absolutely delimited by the edge of the range of  Thecadactylus, with the western edge bounded by the Andes, and the south-eastern extent of the range defined by the edge of mesic Amazonia. The northern extent of the range is difficult to determine with current specimen availability, but may be defined by the Colombian Cordillera Oriental. The eastern range boundary tentatively approximates the political boundary between the Brazilian states of Amazonas and Pará, as inferred from molecular sampling ( Kronauer et al., 2005). More intensive sampling is required to determine the northern and eastern boundaries more definitively.  Etymology: The specific epithet,  solimoensis, is a locative adjective referring to the drainage of the Solimões River, representing the headwaters of the Amazon River, and draining much of the area in which  Thecadactylus solimoensisoccurs. IND, IV, V L. J. Vitt Ecuador Estacion Biologia da Universidad Catolica 12 351 1 Sucumbios holotype