Taxonomic Status and the Phylogenetic Placement ofAmphisbaena leucocephalaPeters, 1878 (Squamata, Amphisbaenidae)

Comparative skull osteology of Amphisbaena arda and Amphisbaena vermicularis (Squamata: Amphisbaenidae)

“…While the phylogenetic position of A. arda is yet unknown (Graboski et al, 2022), it likely shares a close relationship with A. vermicularis due to similarities in external morphology. Both species would belong to a clade of large‐sized amphisbaenids with a putative skull synapomorphy identified as the external surface of the nasal bone with small foramina continuous with a posterodorsal canal opening in the nasal chamber (Dal Vechio et al, 2016). According to Rodrigues (2003), the head scales of A. vermicularis are characteristically swollen, with a middorsal occipital depression marked by a sulcus, in contrast to A. arda .…”

“…Using CT scans, we explored the skull osteology of two worm lizard species, Amphisbaena arda and A. vermicularis . Although the skull of A. vermicularis was previously illustrated (Gans & Montero, 2008; Dal Vechio et al, 2016), it had not been described in detail. Moreover, this study presents the first detailed description of the skull of A. arda .…”

“…Brazil has the greatest richness of amphisbaenian species, with over 80 described species (Costa et al, 2022), yet most of these are overlooked in terms of skull anatomy (but see Gans & Montero, 2008; Montero & Gans, 1999; Ribeiro et al, 2015; Dal Vechio et al, 2016; Vieira et al, 1980). Among the Brazilian worm lizards, we highlight two similar species, Amphisbaena vermicularis Wagler, 1824 and Amphisbaena arda Rodrigues, 2003 "2002".…”

“…Skull anatomy is therefore of great importance in amphisbaenian systematics (Kearney, 2003; Montero & Gans, 1999), but is still underexplored, likely due to their diminutive sizes (skull lengths typically < 2 cm) and scarcity of specimens for most species. Recent advances in technology, such as X‐ray computed tomography (CT), reduce some handicaps related to preparing and describing skull anatomy in these taxa (e.g., Hipsley et al, 2016; Kearney et al, 2005; Maisano et al, 2006; Teixeira Junior et al, 2019; Dal Vechio et al, 2016), although basic information on skull morphology is still undescribed for many worm lizard species (Gans & Montero, 2008), as well as inter‐ and intraspecific variation (Villa et al, 2019). As the skull morphology of amphisbaenians has a direct impact on their burrowing ability, which in turn influences their niche (Navas et al, 2004), describing the anatomy of worm lizard skulls is critical to understanding their evolution and ecology.…”

An updated diagnosis of the rare Amphisbaena slateri Boulenger, 1907, based on additional specimens (Squamata, Amphisbaenia, Amphisbaenidae)

“…Ten Neotropical species (A. albocingulata, A. darwinii, A. hogei, A. manni, A. mensae, A. munoai, A. nigricauda, A. prunicolor, A. schmidti, and A. talisiae), from Argentina, Brazil, Hispaniola, Paraguay, and Puerto Rico (Gans 2005), share many morphological similarities with A. slateri. The phylogenetic relationships of most of them -A. slateri included -is not known (Dal Vechio et al 2016), but it would be of no surprise if later it is found that such similarities are due to convergent evolution, as had been recently discovered for some taxonomically important morphological characters like the head shape (Kearney andStuart 2004, Mott andVieites 2009).…”