Kaieteurosaurus hindsi KOK, 2005
Can you confirm these amateur observations of Kaieteurosaurus hindsi?
|Higher Taxa||Gymnophthalmidae (Cercosaurinae s.l., Ecpleopodinae), Sauria, Gymnophthalmoidea, Squamata (lizards)|
|Synonym||Kaieteurosaurus hindsi KOK 2005|
|Distribution||Guyana (Kaieteur National Park, Potaro-Siparuni district)|
Type locality: on Tukeit trail, ca. 1,250 m NEE from the beginning of the Kaieteur National Park airstrip (from point closest to the gorge), 420 m elevation, Kaieteur National Park, Potaro-Siparuni district, Guyana.
|Types||Holotype: IRSNB 2628, an adult male, Royal Belgian Institute of Natural Sciences, collected by Philippe Kok, Hemchandranauth Sambhu, Reuben Williams and Festus Marco, 23 November 2004.|
|Diagnosis||Diagnosis (genus and species): A small (44.4 mm SVL) gymnophthalmid lizard with cylindrical, slightly depressed body, tail long, round in cross section, without longitudinal ridges. Ear opening present. Limbs well developed, pentadactyl, with all digits clawed. Nasals divided, separated by an undivided frontonasal. Prefrontals absent. Loreal separated from labials by nasal and frenocular. Complete supraciliary series; anterior supraciliary large, not expanded dorsally. Lower eyelid with semi-transparent disc, consisting of six palpebrals. Frontoparietals and occipitals present. Interparietal heptagonal with a straight posterior edge. Interparietal and parietals of approximately same length, forming a more-or-less straight line across the rear of the head (posterior margin of parietals and interparietal slightly convex due to the shape of parietals). Dorsal head scales smooth. Single postmental scale followed by two pairs of large genials in contact with labials and a third pair, much smaller, separated from the labials. Gular scales in transverse rows, first two rows of subequal scales, followed by three rows with a central pair of enlarged scales. Collar with seven scales, the three central ones largest, forming a scalloped posterior border. Dorsals lanceolate (appearing hexagonal because of imbrication), strongly keeled, strongly mucronate, in transverse rows only, ventrals lanceolate (appearing hexagonal because of imbrication), smooth, strongly mucronate, in transverse rows only. Dorsals and laterals of equal size. Tongue with oblique plicae anteriorly and posteriorly; midsection with scalelike papillae. By this unique combination of characters the new genus is readily distinguishable from all other known South American gymnophthalmids. In having hexagonal ventral scales that do not form longitudinal rows and the lingual plicae interrupted by a midsection of scalelike papillae, Kaieteurosaurus most closely resembles Ecpleopus from southeastern Brazil, but is distinctive in many ways, in particular in having a larger head, quadrangular gular scales (gular scales mucronate in Ecpleopus), six paramedian gular scales enlarged toward collar (no enlarged paramedian gular scales in Ecpleopus), no prefrontals, divided nasal (single in Ecpleopus), first supraocular separated from frontonasal by frontal-loreal contact (first supraocular touching both loreal and frontonasal in Ecpleopus), complete supraciliary series (incomplete in Ecpleopus), interparietal heptagonal with a straight posterior margin (interparietal hexagonal, posteriorly slightly projecting in Ecpleopus), proportionally longer fingers, two enlarged thenar scales with produced inner edge (edge not produced in Ecpleopus), ventrals narrower and much more lanceolate (as sharply pointed as the dorsals in Kaieteurosaurus versus less sharply pointed than the dorsals in Ecpleopus), and presence of femoral pores in males (absent in Ecpleopus). In having hexagonal and strongly mucronate ventral scales, Kaieteurosaurus could be confused with Leposoma of the scincoides group from the Brazilian Atlantic forests, but these species are distinctive mainly by the tongue morphology, in having keeled ventral scales (smooth in Kaieteurosaurus), mucronate gular scales (quadrangular gular scales in Kaieteurosaurus), longitudinal striations on head scales (no striations in Kaieteurosaurus) and in lacking occipitals (present in Kaieteurosaurus). In having oblique plicae on the anterior and posterior part of the tongue, Kaieteurosaurus also resembles Adercosaurus, Alopoglossus, Ptychoglossus and Riolama, agreeing only with Adercosaurus and Riolama in having a midsection of scalelike papillae between the anterior and posterior plicae (tongue entirely plicate in Alopoglossus and Ptychoglossus), but these two genera are distinctive in having the interparietal posteriorly projecting, forming a jagged or irregular line (parietals and interparietal forming a more-or-less straight line across the rear of the head in Kaieteurosaurus), and in having quadrangular ventral scales in transverse and longitudinal rows (hexagonal ventral scales in transverse rows only in Kaieteurosaurus). In addition, Riolama also differs from Kaieteurosaurus in lacking claw on the first finger (see MYERS & DONNELLY, 2001: 52). Kaieteurosaurus could also be confused with Arthrosaura but is easily distinguished, primarily by the tongue morphology, in having hexagonal ventral scales in transverse rows only (quadrangular ventral scales in transverse and longitudinal rows in Arthrosaura), in having smooth scales on the forelimbs (keeled in Arthrosaura), and in having a divided nasal (undivided in Arthrosaura) [from KOK 2005].|
|Comment||Type species: Kaieteurosaurus hindsi KOK 2005 is the type species of the genus Kaieteurosaurus KOK 2005.|
Subfamily: the subfamilial classification of this genus is still unresolved (T. Doan, pers. comm., 2 Jun 2014).
For diagnostic morphological characters distinguishing Marinussaurus, Amapasaurus, Anotosaura, Arthrosaura, Colobosauroides, Dryadosaura,Ecpleopus, Kaieteurosaurus, Leposoma, and Pantepuisaurus see Table 2 in PELOSO et al. 2011.
Abundance: only known from the type specimen (Meiri et al. 2017).
|Etymology||The genus has been named after the Kaieteur National Park where the type species occurs, the connecting –o, and the Greek “sauros” meaning “lizard”. The gender is masculine. The specific epithet is a patronym honouring the Prime Minister of Guyana, Mr. Samuel Hinds who kindly granted permission to conduct our study in the Kaieteur National Park; without his enthusiastic support our research would not have been possible.|