Arthrosaura synaptolepis DONNELLY, MCDIARMID & MYERS, 1992
Can you confirm these amateur observations of Arthrosaura synaptolepis?
Arthrosaura synaptolepis
We have no photos, try to find some by Google images search: 
| Higher Taxa | Gymnophthalmidae (Ecpleopodinae), Sauria, Gymnophthalmoidea, Squamata (lizards) |
| Subspecies | |
| Common Names | E: Donnelly's Arthrosaura |
| Synonym | Arthrosaura synaptolepis DONNELLY, MCDIARMID & MYERS 1992 Arthrosaura synaptolepis — MYERS & DONNELLY 1997 |
| Distribution | Venezuela, Brazil (Cerro de la Neblina and Pico Tamacuari in the borderland between Venezuela and Brazil). Elevation 1400 m. Type locality: “about 6.2 km NNE Pico da Neblina, 1400-1450 m, Cerro de la Neblina, Amazonas, Venezuela (00° 51’ 45’’ N, 65° 58’ 52’’ W).” |
| Reproduction | oviparous |
| Types | Holotype: USNM 317882, paratypes: MBUCV, AMNH. |
| Diagnosis | Diagnosis. A small highland species of Arthrosaura that differs from all others in lacking prefrontals and in having two pairs rather than three pairs of genials. See Intra-generic comparisons for additional differences between Arthrosaura synaptolepis and the four other currently recognized species (kockii, reticulata, tyleri, versteegii). Comparisons. Arthrosaura synaptolepis differs from A. kockii in the number of supraoculars (3 vs. 4), size, morphology, and number of tem poral scales (large and smooth in 4 rows vs. small and keeled in 8 rows), size and shape of lateral neck scales (moderate and round vs. small and granular), degree of keeling of dorsal scales (weakly vs. strongly keeled), presence or absence of keels on dorsal limb scales (smooth vs. keeled), color pattern (no middorsal light stripe vs. middorsal light stripe present), and amount of overlap be tween adpressed limbs (slight, 1-2 lateral scales vs. substantial, 6+ scales). Arthro saura kockii usually has a proportionately longer head than A. synaptolepis (based on data presented for A. kockii by Hoogmoed 1973: table 14 [excluding data for RMNH 15226, for which HL seems too small for the given SVL]): Ratio of head length to SVL in A. synaptolepis is 0.19-0.22 (0.206 ± 0.015, n = 3); HL/SVL in A. kockii is 0.20-0.30 (0.266 ± 0.019, n = 42). See Ta ble 2 for differences in ratios and selected scale counts among A. synaptolepis and the remaining three species of Arthrosaura {re ticulata, tyleri, and versteegii)— all charac terized by three supraoculars. Arthrosaura synaptolepis differs from A. versteegii in having fewer and larger tem porals (4 rows vs. 6-7 rows), size of lateral neck scales (moderate vs. small), size of scales in axilla and groin (small vs. granu lar), and morphology of the subcaudal scales (pentagonal and imbricate vs. rectangular and juxtaposed). Arthrosaura synaptolepis was compared with several specimens of A. reticulata col lected at the base of Cerro de la Neblina, a sample that agrees with the account of re ticulata being prepared by Hoogmoed & Avila Pires (pers. comm.). Arthrosaura syn aptolepis differs from these specimens in the number and size of temporal scales (4 rows of large scales vs. 6-7 rows of small scales), size of lateral neck scales (moderate vs. small), size of scales in axilla and groin (small vs. granular), degree of keeling of dorsal body scales (weakly vs. moderately keeled), amount of overlap between adpressed limbs (slight, 1-2 lateral body scales vs. moderate to substantial, 3-6 scales), and details of pigmentation (dorsal body scales with dark margins vs. dorsal scales irregularly flecked with black). The apparent common tenden cy of males to have darker flanks and more distinct pale lateral spots on flanks and tails than females is more strongly pronounced in reticulata than in synaptolepis (Fig. 2). Arthrosaura synaptolepis differs from A. tyleri, the other tepui species, in degree of keeling of dorsal body scales (weakly vs. strongly keeled), shape of median subcaudal scales (pointed vs. rounded posterior mar gins), ventral pigmentation (immaculate ventrals vs. heavily pigmented ventrals, see Fig. 4), and amount of overlap of adpressed limbs (slight, 1-2 lateral body scales vs. moderate, 3-4 scales). Heretofore, Arthrosaura tyleri (Fig. 4) was only known from the type series of three females from over 2000 m elevation on the summit of Cerro Duida. An additional spec imen referable to A. tyleri is from 1750 1 800 m on Meseta de Jaua, roughly 200 km NE of Duida. Although the Jaua specimen has a more rounded snout than the Duida types and an extra genial on the left side, we were unable to otherwise distinguish it morphologically. The Jaua lizard, a male, is darker than the females from Duida and has a series of light dorsolateral spots, but these differences are suggestive of the sexual dichromatism in A. synaptolepis and A. re ticulata. Ruibal (1952:512), in removing tyleri from Pantodactylus, suggested that Arthro saura tyleri was related to A. kockii, but gave no reasons that exclude a close relationship with one of the species with three supra ocular scales. In any case, under the as sumption that some unknown portion of the morphological resemblance reflects synapo morphy, Arthrosaura synaptolepis may be the closest relative (sister species) of A. ty leri. These "tepui species" have fewer mid body scale rows, temporal rows, and sub-digital lamellae (Table 2) than lowland Arthrosaura. The low number of midbody scale rows is a manifestation of the rela tively large dorsal and ventral scales of Ar throsaura synaptolepis and A. tyleri. Simi larly, these are the only species with large smooth scales in the temporal region, ac counting for the low number of temporal rows. The tepui species, Arthrosaura reticu lata, and A. versteegii have three supraocu lars and differ from A. kockii which has four. The highland localities of the presumed sister species, Arthrosaura synaptolepis and A. tyleri, are well separated. The two tepuis from which tyleri is known are roughly 200 km apart and the two localities for synap tolepis are about 1 50 km from one another. The closest localities (Duida and Tamacua ri) between the northern tyleri and the southern synaptolepis are 250 km apart. In traspecific variation in the genials of A. ty leri helps explain the origin of one of the two autapomorphies of A. synaptolepis. [from Donnelly et al. 1992]. |
| Comment | Arthrosaura synaptolepis differs from all other Arthrosaura in lacking prefrontal scales and in having two (vs. three) pairs of genials. Distribution: although the species has been found near the border to Brazil, there are technically no reports from Brazil itself, hence COSTA & BERNILS 2015 do not list this species for Brazil. |
| Etymology | from the Greek synaptos = joined together, and lepis = scale, referring to the apparent fusions that gave rise to the reduced number of head plates in this species. |
| References |
|
| External links |