Increasing taxon sampling suggests a complete taxonomic rearrangement in Echinantherini (Serpentes: Dipsadidae)

Although the recent advances on the relationship of its major groups, the systematics of the rich fauna of Neotropical snakes is far from being a consensus. In this sense, derived groups presenting continental distributions have represented a main challenge. The taxonomy of the snake tribe Echinantherini is one of the most contentious among the diverse family known as Dipsadidae. The tribe is poorly sampled in phylogenetic studies, resulting in conflicting hypotheses of relationships among its taxa. Moreover, several rare and micro endemic species of Echinantherini have never been evaluated within a comprehensive phylogenetic framework. Here, we assess for the first time the phylogenetic position of the rare Echinanthera amoena within Echinantherini. We based our analyses on a comprehensive multilocus dataset including 14 of the 16 species described for the tribe. Our results support the monophyly of Echinantherini and strongly indicate E. amoena as a unique lineage, phylogenetically positioned apart from all other congeners. From the three current genera (Echinanthera, Taeniophallus, and Sordellina) our results indicate that Echinanthera and Taeniophallus are paraphyletic, since the T. affinis species group is positioned as sister to Echinanthera (except E. amoena) clustering apart from the clade formed by the T. brevirostris and T. occipitalis groups. We describe new genera for the T. affinis and T. occipitalis species groups and an additional monospecific genus for E. amoena. Although we did not evaluate the phylogenetic position of T. nebularis, we described a new genus and removed it from Echinantherini since its morphology strikingly departs from all species now included in the tribe. Finally, we redefine the genera Echinanthera and Taeniophallus and we provide comments about further directions to study the biogeography and the evolution of morphological traits in Echinantherini.

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.

Envenomation caused by Rhopalurus amazonicus Lourenço, 1986 (Scorpiones, Buthidae) in Pará State, Brazil

Scorpions, mainly those belonging to the genus Tityus cause many deaths and injuries in Brazil, with tens of thousands of envenomations notified every year. However, injuries involving other scorpion species are scarcely registered. Among the sixteen species of the genus Rhopalurus, Thorell, 1876, described up to date, nine are found in this country, with only a confirmed case of human envenomation provoked by R. agamemnonKoch, 1839. The present case reports, for the first time, a case of scorpion sting in a human victim involving Rhopalurus amazonicus, endemic species of the west region of the Pará state, Amazon, Brazil. The symptoms of envenomation were local pain and paresthesia. This study contributes to develop the knowledge on venomous scorpions, particularly those that may cause envenomations in this region.