Kentropyx Spix

Harvey, Michael B., Ugueto, Gabriel N. & Gutberlet, Ronald L., 2012, 3459, Zootaxa 3459, pp. 1-156 : 124-127

Kentropyx Spix

Figure 71

Kentropyx Spix 1825: 21 . Type species Kentropyx calcaratus Spix by monotypy.

Pseudameiva Fitzinger 1826: 21. Type species Lacerta striata Daudin by monotypy.

Trachygaster Wagler 1830: 154 . Type species Kentropyx calcaratus Spix.

Acanthopyga Gray 1838:278 . Type species Lacerta striata Daudin by monotypy.

Diagnosis.— Kentropyx is the only genus of teiids with scales between the digital lamellae continuing as a row of enlarged scales between the fourth and fifth toe and relatively long, apical papillae on the lobes of the hemipenis. Unlike all other Teiidae , Kentropyx apparently lacks visible subterminal lenticular scale organs on its dorsals and caudals. No other Teiinae has keeled ventrals (also in Dracaena ) or relatively small, keeled antebrachials (small antebrachials that are either keeled or smooth occur in Callopistes and the various genera of Tupinambinae ). Unlike other Teiinae , Kentropyx lacks a subocular keel or has a weak keel restricted to the first and second subocular, but not extending to the long subocular below the eye.

Content.— Kentropyx altamazonica Cope , Kentropyx borkiana Peters , Kentropyx calcarata Spix , Kentropyx lagartija Gallardo , Kentropyx paulensis Boettger , Kentropyx pelviceps Cope , Kentropyx striata (Daudin) , Kentropyx vanzoi Gallagher and Dixon , Kentropyx viridistriga Boulenger.

Definition.—Small to medium lizards reaching 127 ( Kentropyx striata ) mm SVL; tail 2.0–2.5X ( Table 14) as long as body; posterior maxillary and dentary teeth longitudinally compressed, tricuspid; pupil reniform.

Prefrontal separated from nasal, usually separated from first supraciliary; frontal entire, lacking longitudinal ridge, its posterior suture contacting second supraocular; scales of frontoparietal region smooth, with welldeveloped key-hole shaped depression absent; frontoparietals paired; parietals consisting of three regular scales; interparietal entire; medial pair of enlarged occipitals usually present; occipitals 10–20, usually larger than first row of dorsals; supratemporals slightly to moderately enlarged, separated from parietals by one or more scales.

Rostral groove absent; nostril oval and oriented anteroventrally, its position relative to nasal suture varying among species; loreal single; supraoculars six (rarely eight); first supraocular entire, usually broadly contacting second supraocular ( Kentropyx altamazonica , K. borkiana , K. calcarata , K. pelviceps , K. striata ) or frequently partially to completely separated from second supraocular ( K. lagartija , K. vanzoi , K. viridistriga ); circumorbital semicircles consisting of 0–7 (usually 4) small scales, extending to posterior border of third supraocular or slightly in front of its posterior border; supraciliaries 8–11, separated from supraoculars by 1–2 rows of 12–56 granular scales; first supraciliary long, greater than one-half as long as second; subocular keel absent (most species) or weak and restricted to suboculars 1 and 2 ( K. striata ); suboculars four (rarely 5); first subocular entire, contacting first supraciliary, contacting supralabials or separated from them by anterior expansion of second supralabial (rarely separated from supralabials by scale inserted between suboculars and loreal); patch of slightly to distinctly enlarged scales in front of auditory meatus; auricular flap and preauricular fold absent.

Supralabials 12–14; first supralabial usually subequal to second, its ventral margin straight; infralabials 10–14; first pair of chinshields broadly contacting infralabials, forming medial suture of variable length, separated medially by small granular scales in Kentropyx lagartija and many K. pelviceps and K. viridistriga ; interangular sulcus absent; anterior gulars 18–35; gular patch present ( K. borkiana , K. striata ) or absent (all other species); posterior gulars 6–16; intertympanic sulcus absent; anterior and posterior gulars subequal, not undergoing transition at intertympanic crease; mesoptychials distinctly ( K. striata ) to moderately (all other species) enlarged, not forming differentiated transverse row; gular fold lacking serrated edge.

Dorsals keeled; not projecting laterally, supported by small apical granules; scales on flank much smaller than ( Kentropyx borkiana , K. striata ) or subequal to (all other species) middorsals; scales on rump much smaller ( K. altamazonica , K. calcarata , K. pelviceps ) or slightly smaller ( K. borkiana , K. lagartija , K. striata , K. vanzoi , K. viridistriga ) than proximal subcaudals; scales of chest large, keeled; pectoral sulcus absent; ventrals keeled, mucronate, in 31–41 transverse and 12–16 (usually 14) longitudinal rows; lateral-most ventrals flanked by small scales (i.e., ventrals not gradually decreasing in size on flanks); preanals 4–6 (usually 4 or 5); preanal plate present, consisting of keeled scales similar to ventrals; preanal spurs 2/2, each narrow and attenuate, extending next to body, separated from preanal plate by large (i.e., as long as base length of spur) scales; small vestigial spur usually present, positioned above and behind larger spurs; postcloacal buttons and postanal plates absent; scales on dorsolateral edge of tail like those on top and sides, denticulate edge and dorsolateral crests absent; caudal annuli complete; proximal subcaudals keeled.

Dorsal surface of arm covered by enlarged, subtriangular, keeled scales; preaxial and postaxial brachial scales longer than wide; preaxial antebrachial scales relatively small, subtriangular, keeled; postaxial antebrachial scales granular ( Kentropyx altamazonica ) to slightly enlarged (all other species); subdigital lamellae of hand homogeneous ( K. altamazonica , K. striata ), heterogeneous with noticeably larger subarticular lamellae ( K. borkiana , K. calcarata , K. pelviceps ), or with mostly divided subarticular lamellae ( K. lagartija , K. vanzoi , K. viridistriga ), 14–19 under fourth finger.

Prefemorals 8–19; femoral and abdominal pores 12–43 in continuous row on each side (abdominal pores not separated from femoral pores by gap); each compound pore-bearing scale consisting of partially fused prefemoral or abdominal scale and 2–6 granular scales; 2–7 scales separating right and left pore rows; scales at heel small and numerous; tibiotarsal shields and spurs absent; lamellae under fourth toe 21–29; distal lamellae of fourth toe smooth ( Kentropyx lagartija , K. viridistriga ) or keeled (all other species); scales between subdigital and supradigital lamellae of toes serrate ( K. lagartija , K. viridistriga , K. vanzoi ) or denticulate ( K. altamazonica , K. borkiana , K. calcarata , K. pelviceps , K. striata ), continuing as row of noticeably enlarged postaxial scales between fourth and fifth toe; fifth toe well-developed, base of its claw extending beyond level of skin between third and fourth toes when adpressed.

β- keratin containing layers of dorsal scales folded into short macroridges; dorsal, ventral, and caudal scales lacking apparent subterminal lenticular scale organ (although lenticular scale organs present on scales of head and neck); generation glands absent.

Snout same color as dorsal head scales, some specimens of Kentropyx calcarata with red heads but color not restricted to snout. In juveniles, light vertebral stripe solid and straight ( Kentropyx altamazonica , K. calcarata , K. vanzoi ), widening substantially on posterior body ( K. lagartija , K. pelviceps , K. viridistriga ), or absent ( K. striata ); light paravertebral stripes absent; dark dorsolateral field solid ( K. vanzoi , K. viridistriga ), solid anteriorly and breaking into blotches posteriorly ( K. pelviceps , K. striata ), or absent ( K. altamazonica ); dorsolateral light stripe solid and extending to tail ( K. altamazonica ), fading towards head or sacrum ( K. lagartija , K. vanzoi , K. viridistriga ), or absent ( K. calcarata , K. pelviceps , K. striata ); dark lateral field solid (most species) or absent ( K. pelviceps ); upper lateral light stripe extending above leg (most species) or solid and extending to groin ( K. altamazonica ); lower lateral light stripe solid to groin ( K. lagartija , K. striata , K. vanzoi , K. viridistriga ), broken and extending to groin ( K. calcarata ), or absent ( K. altamazonica , K. pelviceps ); thigh lacking light spots. In adult males, light spots on flanks absent (most species) or small and numbering around 17 ( K. calcarata ), 35 ( K. pelviceps ) or 36 ( K. striata ); turquoise ventrolateral spots absent; venter immaculate, lacking melanic areas; juvenile dorsal color pattern present in adult males with only slight to moderate modification ( K. altamazonica , K. pelviceps , K. striata , K. vanzoi ) or completely absent ( K. calcarata , K. lagartija , and K. viridistriga ).

Hemipenis lacking apical awns and circular apical basin; relatively long apical papillae present, densest between lobes where they interrupt sulcus; asulcate expansion pleat absent; about 26–35 (based on two species) laminae encircling body of organ, interrupted; basal papillae absent.

Etymology.— Kentropyx is a feminine noun in the nominative singular derived from the Greek words kentron meaning spur and pyxos meaning box. The name is likely an allusion to the preanal spurs in species of this genus.

Distribution.— Cis-Andean South America, Barbados, and Trinidad.

Interspecific Relationships.— Gallagher and Dixon (1980, 1992) recognized three species groups within Kentropyx . In our survey of morphological characters, we identified additional characters that strengthen the diagnoses of these groups. These characters proved useful in species identification and will likely aid in the diagnosis of undescribed species of this genus.

The phylogeny of Kentropyx ( Fig. 72) has been investigated using morphology (this study; Werneck et al. 2008), mtDNA (Werneck et al. 2008), and combined mtDNA and allozymes (Reeder et al. 2002). Each analysis recovered the species groups proposed by Gallagher and Dixon (1980; 1992). However, the phylogenies differ in both the relationships among and within groups. Interestingly, three previous hypotheses have strong bootstrap support for all branches ( Fig. 72), even though the topologies are considerably different from one another.

Remarks.— Herein, we make one correction to the synonymy of Kentropyx: Gray proposed the junior synonym Acanthopyga in 1838 rather than in his later Catalogue ( Gray 1845) as thought by Peters and Donoso-Barros (1970).