A new species of the Amphisbaena (Squamata, Amphisbaenidae) from the Brazilian Cerrado with a key for the two-pored species.

Here, we describe a new species of Amphisbaena with two precloacal pores from open Cerrado areas of the municipality of Arenópolis, in the Brazilian state of Goiás. The new species differs from other South American amphisbaenids by the folllowing combination of characters: (1) snout rounded in dorsal view and slightly convex in lateral view; (2) two precloacal pores; (3) 161-176 dorsal half-annuli; and (4) 12-15 tail annuli. Our molecular phylogenetic analysis retrieved a monophyletic Amphisbaena silvestrii group, with A. silvestrii positioned as the sister-group of a clade formed by Amphisbaena anaemariae and the new species described herein. Members of the A. silvestrii group including A. neglecta and A. crisae not added in our phylogenetic analysis are characterized by a relatively small body, two precloacal pores, body coloration with dark and light areas, and lack of specializations on the cephalic or caudal shields. We present a key for two-pored species of Amphisbaena.

A new four-pored Amphisbaena Linnaeus, 1758 (Amphisbaenia, Amphisbaenidae) from Brazilian Amazon.

A new species of Amphisbaena is described from the Brazilian Amazon, within the area impacted by the Teles Pires hydroelectric power plant, Jacareacanga municipality, State of Pará. Amphisbaena hoogmoedi sp. nov. can be diagnosed from its congeners by the following combination of characters: snout convex in profile view, sligthly compressed not keeled; pectoral scales arranged in regular annuli; conspicuous autotomic site between 7th-8th caudal annuli; 247-252 dorsal half-annuli; 27 caudal annuli; tail length 9.5-10.4% of snoutvent length; four precloacal pores arranged in sequence; three supralabials; a rounded tail; 22-24 dorsal segments in midbody annulus; postmalar row absent; head length 2.1-2.9% of snout-vent length; prefrontals length 46.6-49.5% of head length; prefrontals suture length 38-44.6% of head length; small malar length 10.6-13.4% of ventral length of head ; second infralabial length 33.8-38.5% of head length; ventral length of head 2.7-2.9% of snout-vent length; mouth length 80.2-81.8% of head length; third infralabial length 16.4-19.6% of head length; snout length 62.5-78.6% of head length; ocular length 23.4-26.2% of head length; mental length 23.2-25.4% of ventral length of head; postmental length 27.2-31.3% of ventral length of head; frontals suture length 23.4-32.3% of head length; postocular width 25-31.9% of maximun width of head; first supralabial length 24.9-30.6% of head length; second supralabial length 27.7-30% of head length and second supralabial height 26.9-28.8% of maximun head height. The hemipenis is bilobed, capitate and with lateral lamellae on the lobes; with a centrally-positioned spermatic groove, bifurcated at the base of the lobes, and with each branch extending to the tip of organ.

Geographic variation and taxonomy of red-tailed Gymnophthalmus (Squamata: Gymnophthalmidae) from Amazonian Savannas.

Gymnophthalmus represents a challenging group for systematics of microteiid lizards. Due to scarcity of exemplars and molecular data, the taxonomy of the genus has been unstable, and six of its eight species are considered part of a poorly-delimited complex of unisexual and bisexual species. Unnamed populations of red-tailed Gymnophthalmus from savanna enclaves in Amazon, similar to G. vanzoi but with differences in color pattern, have been noted in the literature. Here, we used molecular and morphological data to test the taxonomic status of the Central Amazonian red-tailed Gymnophthalmus (G. sp.). Our molecular analysis recovered a close relationship between G. vanzoi and G. sp. from Central Amazon, with minimal divergence. Samples were similar in scale counts but presented significant variation in color pattern and morphometry. Despite the geographic isolation, individuals of both populations cannot be fully differentiated based on morphology. Thus, our results suggest that G. vanzoi has a wider distribution, including the Central Amazonian red-tailed Gymnophthalmus and likely morphologically similar populations from other enclaves of Amazonian savannas, which may have been isolated recently. Based on our comparative analysis, we highlight some characters proved useful for differentiating Brazilian Gymnophthalmus and discuss some prospects for the taxonomy of the genus.

A new two-pored species of Amphisbaena (Squamata, Amphisbaenidae) from the Brazilian Cerrado, with a key to the two-pored species of Amphisbaena.

A new species of Amphisbaena is described from municipalities of Babaçulândia, State of Tocantins, and Estreito, State of Maranhão, northern Brazilian Cerrado. The new species differs from other two-pored species of the genus, by presenting mainly slender body shape; snout rounded in profile and dorsal view; high number of body annuli (328-342); 12-14 dorsal segments and 14-16 ventral in midbody half-annulus; autotomic site between 9-10th caudal annuli; absence of chevron-shaped anterior dorsal half-annuli; 20-23 caudal annuli; postmalar row absent; and precloacals pores arranged in a continuous series of the precloacal half-annuli. Additionally, we present a key for two-pored species of Amphisbaena.

A new species of Leposternon Wagler, 1824 (Squamata, Amphisbaenia) from northeastern Argentina.

A new species of Leposternon is described from the Humid Chaco biome in Argentina. The species is known only from its type locality, at El Bagual Ecological Reserve, a conservation unit located in the province of Formosa. The new species can be distinguished from all its congeners by the presence of rostral processes in the maxillae and nasals that contact each other on the facial portion of the skull. Additionally, we present a key for the species of Leposternon.