Rheosaurus sulcarostrum (DONNELLY, MACCULLOCH, UGARTE & KIZIRIAN, 2006)
Can you confirm these amateur observations of Rheosaurus sulcarostrum?
|Higher Taxa||Gymnophthalmidae (Cercosaurinae), Sauria, Gymnophthalmoidea, Squamata (lizards)|
|Synonym||Echinosaura sulcarostrum DONNELLY, MACCULLOCH, UGARTE & KIZIRIAN 2006|
Rheosaurus sulcarostrum — VÁSQUEZ-RESTREPO et al. 2019
Type locality: Guyana, Baramita, approximately 1 km S airstrip, 07°22’N, 060°29’W, elevation 100 m.
|Types||Holotype: ROM 22893|
|Diagnosis||Diagnosis (genus Rheosaurus): Phenotypic characteristics of Rheosaurus include: (1) dorsal scales heterogeneous, with large or polygonal, longitudinally keeled scales intermixed with small irregular scales; (2) dorsal surface of the head with large, symmetrical scales; (3) internasal divided; (4) frontonasals three; (5) prefrontals paired; (6) frontal single; (7) frontoparietals paired; (8) interparietal well defined; (9) parietals paired; (10) rostral and mental striated; (11) three rows of scales between rostral and frontal scales; (12) postmental absent; (13) large chin shields in three pairs; (14) lower eyelid developed, with a palpebral disc divided into several, unpigmented scales; (15) ventral scales squared, not imbricated; (16) limbs pentadactyl, digits clawed; (17) femoral pores present in males (weakly developed) and absent in females.|
Rheosaurus differs from all other cercosaurines, including Echinosaura s.s. and its sister-group, in having striated rostral and mental scales and three rows of scales between rostral and frontal scales, and in lacking a postmental scale. It also differs from other cercosaurines, except Centrosaura, Echinosaura s.s., Gelanesaurus, Neusticurus and Potamites, in having heterogeneous dorsal scalation. For comparisons among related or similar genera see Figure 9 and Table 5 in VÁSQUEZ-RESTREPO et al. 2019.
Diagnosis. Echinosaura sulcarostrum is diagnosed from all other gymnophthalmids by the presence of a striated rostral and mental scales, a unique arrangement of scales on the snout including three rows of scales of subequal size between rostral and frontal scales, and by the absence of an unpaired median postmental (from DONNELLY et al. 2006).
|Comment||This species is not part of the Echinosaura clade fide TORRES-CARVAJAL et al. 2016 although they do not assign it to any other genus.|
Abundance: only known from its original description (Meiri et al. 2017).
Type species: Echinosaura sulcarostrum DONNELLY, MACCULLOCH, UGARTE & KIZIRIAN 2006 is the type species of the genus Rheosaurus VÁSQUEZ-RESTREPO et al. 2019.
|Etymology||Rheosaurus (gender masculine) is derived from the Greek ρέω, rheo (flow or stream) and σαύρα, saura (lizard), in reference to the riparian habit of this lizard.|
Named after the Latin words sulcus, meaning furrow or groove, and rostrum, meaning snout.