Morphological similarities between Amphisbaena mitchelli Procter, 1923 and A. miringoera Vanzolini, 1971 (Squamata: Amphisbaenidae): phylogenetic relatedness or morphological convergence?

Abstract

To date, 22 species of amphisbaenids have been recorded at Brazilian Amazon (Ribeiro et al. 2008), six of them are small and have two pre-cloacal pores (Hoogmoed & Ávila-Pires 1991; Teixeira Jr. et al. 2014). Most of these species have narrow distributions, and its biology and phylogenetic relationships are poorly understood (Hoogmoed & Ávila-Pires 1991). Amphisbaena mitchelli Procter, 1923 and A. miringoera Vanzolini, 1971 share several morphological similarities that could reflect phylogenetic relatedness (Vanzolini 1971). Both have two pre-cloacal pores and a similar pattern of head scutelation, but whereas the first has 193-220 and 26-29 body and tail annuli, respectively, the latter has 250-264 and 22-24 (Vanzolini 1971).

UPDATED DISTRIBUTION MAP OF Amphisbaena mitchelli PROCTER, 1923 (SQUAMATA: AMPHISBAENIDAE) WITH A NEW RECORD IN MARANHÃO, BRAZIL

“…Amphisbaena mitchelli Procter, 1923 is a small-sized worm lizard species (up to 162 mm snout-vent length) endemic to northern Brazil (Colli et al, 2016). It is diagnosed by having a round head, 193-220 body annuli, 26-29 caudal annuli with autotomy at the 6th or 7th annulus, two precloacal pores sequentially arranged, dorsal and lateral sulci, 12-14 dorsal and 14-16 ventral segments at a midbody annulus, three supra-and three infralabials (Gans, 1963;Almeida et al, 2016). The species was described from Ilha de Marajó, state of Pará, based on one specimen deposited in the Natural History Museum, London (NHMUK 1946.8.2.31 [former BMNH]) (Procter, 1923;Gans, 1963).…”