Uncovering hidden species diversity of alopoglossid lizards in Amazonia, with the description of three new species ofAlopoglossus(Squamata: Gymnophthalmoidae)

Abstract

Alopoglossus is a Neotropical lizard genus the taxonomy of which has extensively evolved over the past decade. Previous works suggest that many species still remain unnamed in this genus. Here, we expand the knowledge of Alopoglossus diversity in Amazonian lowlands. Molecular phylogenetic relationships, and species boundaries, were inferred based on the variation of mitochondrial (Cytb and ND4) and nuclear (SNCAIP and PRLR) loci. Morphological variation was assessed through analyses of external morphology of 401 specimens, covering the entire distribution range of Alopoglossus angulatus and its closely related taxa, and hemipenes of five specimens were examined. Combined, our evidence supports the recognition of three new species. We describe these species and redefine A. amazonius sensu stricto, increasing the number of known Alopoglossus species to 18. Our study also presents the first detailed descriptions of hemipenes for the genus.

Amphibians and reptiles from a protected area in western Brazilian Amazonia (Reserva Extrativista do Baixo Juruá)

“…Data obtained on our expeditions were relevant to improve the knowledge on the effects of the Juruá River as geographical barriers to amphibians (see Gascon, 1996;Lougheed et al, 1999;Gascon et al, 2000), but also on the taxonomy of Amazonian amphibians and reptiles. For example, the microhylid Chiasmocleis avilapiresae (Peloso & Sturaro, 2008), the aromobatids A. ius and A. gasconi (Morales, 2002), and the gymnophthalmid A. indigenorum (Ribeiro-Júnior et al, 2021) were described using this material. Furthermore, specimens collected at the RBJ also provide relevant geographic novelties, supporting distribution extensions for the allophrynid Allophryne resplendens Castroviejo-Fisher et al, 2012(Carvalho et al, 2017, the leptodactylid A. simonstuarti (Carvalho et al, 2020), the dipsadid Erythrolamprus pygmaeus (Cope, 1868) (Kawashita-Ribeiro et al, 2011), and the viperid Botrocophias hyoprora (Amaral, 1935) (Carvalho et al, 2013).…”

“…Amphibian and reptile species substitutions across Amazonian assemblages are also especially evident considering: (1) the main geological compartments, i.e., sedimentary basin of western Amazonia vs. Quaternary crystalline shields of eastern Amazonia (e.g., Ávila-Pires, 1995;Silva-Jr. & Sites-Jr., 1995;Rojas et al, 2018;Réjaud et al, 2020;Ribeiro-Júnior et al, 2021); and (2) the Amazon River as a geographic barrier, i.e., its northern vs. southern banks (e.g., Silva-Jr. & Sites-Jr., 1995;Godinho & da Silva, 2018;Rojas et al, 2018). Considering these main biogeographic units, the RBJ is inserted at western Amazonia sedimentary basin and at the southern bank of the Amazon River.…”

“…We compared the external morphology (morphometric and meristic characteristics, and coloration patterns) of specimens with original species' descriptions, dichotomous keys, geographically related inventories, and field guides (e.g., Peters & Donoso-Barros, 1986;Dixon et al, 1993;Ávila-Pires, 1995;Gascon, 1996, Lougheed et al, 1999, Gascon et al, 2000Morales, 2002;Peloso & Sturaro, 2008;Moravec et al, 2009;Souza, 2009;Angulo & Icochea, 2010;Maciel & Hoogmoed, 2011;Gordo et al, 2013;Brcko et al, 2013;Fouquet et al, 2014Peloso et al, 2014Peloso et al, , 2016Caminer & Ron, 2014, 2020Caminer et al, 2017;Rivadeneira et al, 2018;Simões et al, 2018;Cunha et al, 2019;Ferrão et al, 2020Ferrão et al, , 2022Sturaro et al, 2020;Magalhães et al, 2020;Rainha et al, 2021;Ribeiro-Júnior et al, 2021), as well as through direct comparisons with other voucher specimens deposited at INPA-H. Evidence for color in life were based on photographs taken during the expeditions of 2005-2007 and 2018. In some cases of the reappraisal of museum specimens, we rely on their external morphology data to determine their updated taxonomic status.…”

“…Both the analyses of molecular and morphological (meristic) variation of a recently collected specimen of the Alopoglossus angulatus (Linnaeus, 1758) species complex from the RBJ showed that it represented an undescribed taxon. This species was then recently described as A. indigenorum, containing the specimen from the RBJ as part of its type series (Ribeiro-Júnior et al, 2021). The species is distributed in the extreme western Brazilian Amazonia, at south of the Amazon River.…”

“…Despite that, our understanding of the Amazonian amphibian and reptile diversity goes through a transition period. The relatively recent implementation of molecular data in integrative approaches has significantly increased our understanding regarding how these vertebrates have diversified in this ecosystem (e.g., Réjaud et al, 2020;Carvalho et al, 2021), and in their taxonomic boundaries and geographic distributions (e.g., Ferrão et al, 2016;Peloso et al, 2016;Ribeiro-Júnior et al, 2021;Vacher et al, 2020). At the same time, molecular elucidation also highlighted how much we still do not know about this diversity, at different scales of knowledge (Jaramillo et al, 2020;Vacher et al, 2020).…”