When the tail shakes the snake: phylogenetic affinities and morphology of Atractus badius (Serpentes: Dipsadidae), reveals some current pitfalls on the snake’s genomic age

Abstract

Atractus badius has a long and controversial nomenclatural history due to both its antiquity and the brevity of its original description. This species was described based on two syntypes from Java. Later, a lectotype was designated and the distribution range restricted to the Guiana Shield. Although this species has been repeatedly recorded throughout Amazonia and the Andes, these records have been erroneously assigned to A. badius because of a considerable level of confusion in the literature. We found 13 additional specimens of this poorly known snake, expanding our knowledge on its morphological variability, phylogenetic relationships and distribution. In this paper, we report new localities and data on meristic, morphometric, coloration, scales micro-ornamentation, osteology and hemipenial morphology to A. badius. We also determine the phylogenetic position of A. badius as nested in a composite Guiana Shield clade. In addition, we discuss recent advances on the systematics of Atractus and comment on some 'new arrangements' with respect to previously recognized species groups and available morphological evidence. Finally, we highlight the importance of accurate voucher identifi cation before promoting taxonomic changes or implementing nomenclatural acts derived from new phylogenetic hypotheses, and notably propose the synonymy of the recently described A. pyroni with A. roulei.

Leaving no stone unturned: three additional new species of Atractus ground snakes (Serpentes, Colubridae) from Ecuador discovered using a biogeographical approach

“…1) and ML (Suppl. material 2: Figure S1) analyses are similar to that of Arteaga et al (2017) and Passos et al (2022). Species of the Atractus roulei species group are sister to all other sampled Atractus in the BI analysis, a view contrary to the ML analysis and to Murphy et al (2019), in which A. trilineatus Wagler, 1928and A. boimirim Passos et al, 2016, respectively are recovered as sister to all other Atractus.…”

“…Species of the Atractus roulei species group are sister to all other sampled Atractus in the BI analysis, a view contrary to the ML analysis and to Murphy et al (2019), in which A. trilineatus Wagler, 1928and A. boimirim Passos et al, 2016, respectively are recovered as sister to all other Atractus. Below, we outline some differences between our analysis and those published in Murphy et al (2019) and Passos et al (2022).…”

“…Based this evidence, we also consider A. occidentalis to be a junior synonym of A. microrhynchus. Recently, Passos et al (2022) provided a list of reidentifications of 15 (not 17, because two are duplicates and MZUTI 4178 retained the same identification despite being listed in the table) Atractus specimens having sequences deposited in GenBank, notably among them the members of the A. iridescens species group deposited in MZUTI and DHMECN. In this work, one reidentification (that of the holotype of A. pyroni; MZUTI 5107) was backed up by ample evidence and two oth- ers (ANF 2390, now MZUTI 5409;and GFM 307, now MPEG 21582) were substantiated in Melo-Sampaio et al ( 2021), but the remaining were proposed without providing any evidence, either in the form of new phylogenetic relationships, new scale counts, or previously unsampled morphological features.…”

“…Since these specimens are deposited at MZUTI and DHMECN, as well as their corresponding photo vouchers available in Arteaga et al (2017), and their DNA sequences on GenBank, their identity can be tested by anyone. Although the reidentification of the remaining specimens provided by Passos et al (2022) was unsubstantiated, not all of them were unwarranted (see Table 4). We agree that DHMECN 7644 (identified as A. lehmanni Boettger, 1898 in Arteaga et al 2017) and IBSP 71932 (identified as A. zebrinus Jan, 1862 in Grazziotin et al 2012) are misidentified, but their new identifications provided by Passos et al (2022) are not correct either (see Table 4).…”

The geographic distribution of Atractus lehmanni (Boettger, 1898) (Serpentes, Colubridae, Dipsadinae) in Colombia, and clarification of its status and type locality in Ecuador

“…Moreover, over 12 years of field surveys for snakes by A. Arteaga and colleagues have failed to find any specimens that fit the description of A. lehmanni in or near the reported type locality of Cuenca (Boettger 1898) or elsewhere in Ecuador. Instead, specimens from Ecuador identified as A. lehmanni (Arteaga et al 2017) have subsequently been identified as A. roulei in a more recent work (Passos et al 2022) that includes a more comprehensive taxon sampling. These specimens have dorsal scales arranged in 15 rows at mid-body, as opposed to the diagnostic 17 rows of A. lehmanni.…”