Amphisbaena filiformis RIBEIRO, GOMES, RODRIGUES DA SILVA, CINTRA & DA SILVA, 2016
Can you confirm these amateur observations of Amphisbaena filiformis?
|Higher Taxa||Amphisbaenidae, Amphisbaenia, Lacertoidea, Squamata|
|Synonym||Amphisbaena filiformis RIBEIRO, GOMES, RODRIGUES DA SILVA, CINTRA & DA SILVA 2016|
|Distribution||Brazil (Tocantins: Babaçulândia and Estreito municipalities)|
Type locality: municipality of Babaçulândia (07o14’45” S, 47o46’38” W, 156 m), State of Tocantins, Brazil
|Types||Holotype: MPEG 27916 (field number: EDR 730), an adult male, collected on 01 February 2010 by Carlos Eduardo D. Cintra. Paratypes. Male: MPEG 27917; indeterminate sex: MPEG 27915, MPEG 27918 and MPEG 27919; same data as the holotype, but collected on 08 February 2010. Males: MZUSP 102046, MZUSP 102048, MZUSP 102049 and MZUSP 102044; female: MZUSP 102047 and MZUSP 102045; all from Estreito municipality (06°35'13" S, 47°27'39" W), State of Maranhão, Brazil, collected by Carlos Eduardo D. Cintra, between 18 January and 27 April 2011.|
|Diagnosis||Diagnosis. (1) snout rounded; (2) 328–342 body annuli; (3) absence of major fusion of head shields, being shields of dorsal, lateral and ventral head portion distincts; (4) two precloacal pores; (5) 12–14 dorsal and 14–16 ventral segments per midbody annulus; (6) autotomic site between 9–10th caudal annuli; (7) absent of chevron-shaped anterior body annuli; (8) precloacals pores arranged in a continuous series of the precloacal half-annuli; (9) 20–23 caudal annuli; (10) distinct dorsal sulci; (11) head slightly thiner than trunk; (12) tail tip slightly compressed; and (13) postmalar row absent.|
Comparisons. Amphisbaena filiformis is a small to medium species (232 mm of maximum snout-vent length) and slender body shape and can be distinguished the other South American amphisbaenians species by a combination of characters. Differs from Amphisbaena acrobeles (Ribeiro, Castro-Mello & Nogueira, 2009), Amphisbaena anomala, Amphisbaena bilabialata, Amphisbaena kingii (Bell, 1833), Leposternon cerradensis Ribeiro, Vaz-Silva and Santos-Jr, 2008, Leposternon infraorbitale (Berthold, 1859), Leposternon kisteumacheri Porto, Soares & Caramaschi, 2000, Leposternon maximus Ribeiro, Nogueira, Cintra, Silva Jr. & Zaher, 2011, Leposternon microcephalum Wagler, 1824, Leposternon octostegum (Duméril & Duméril, 1851), Leposternon polystegum (Duméril & Duméril, 1851), Leposternon scutigerum (Hemprich, 1820), Leposternon wuchereri (Peters, 1879), Mesobaena huebneri Mertens, 1925 and Mesobaena rhachicephala Hoogmoed, Pinto, Rocha & Pereira, 2009 mainly by having snout rounded in profile and dorsal view (vs. snout shovel-like or compressed forming a sharp and prominent keel) (see details of cited species in original descriptions and studies of Gans 1971a; Gans 1971b; Mott et al. 2008; Hoogmoed et al. 2009; Ribeiro et al. 2009; Ribeiro 2010).
It differs from all others Amphisbaena species with rounded snout, except of A. supernumeraria Mott, Rodrigues & Santos, 2009 by having more than 327 body annuli (vs. less than 287 annuli). Differs from A. supernumeraria by having rostral, nasal prefrontals and frontals shields distinct (vs. a single large scale corresponding to those scales); two precloacals pores (vs. four); 14−16 ventral segments per midbody annulus (vs. 17–18); and conspicuous autotomic site between 9–10th caudal annuli (vs. discrete autotomic site between 10–12th caudal annuli). It also differs from A. supernumeraria by not having the anteriormost body annuli chevron-shaped (vs. anteriormost annuli chevron-shaped).
Furthermore, the new species can be specifically distinguished from other known South American species of Amphisbaena with two precloacals pores (see details of meristic and morphometric characters in Table 1) by having rounded snout (vs. depressed snout in A. anomala; compressed in A. bilabialata; and slightly compressed in A. absaberi, A. carli and A. roberti); 328–342 body annuli (vs. less than 265 annuli or more than 353 annuli); two precloacals pores arranged in a continuous series of the precloacal half-annuli (vs. precloacals pores with a median hiatus in A. absaberi, A. carli and A. hiata; and disposed in the lateral of cloaca in A. anomala); 20–23 caudal annuli (vs. less than 19 in A. absaberi, A. anomala, A. bilabialata, A. brevis, A. carli, A. dubia, A. heterozonata, A. hiata, A. leeseri and A. neglecta); 12–14 dorsal segments in midbody half-annulus (vs. 10 in A. caiari and A. crisae; and more than 15 in A. absaberi, A. brevis, A. anomala, A. bilabialata, A. carli and A. hiata); 14–16 ventral segments in midbody half-annulus (vs. 10 in A. caiari and A. crisae; and more than 17 in A. carli, A. heterozonata and A. hiata); distinct dorsal sulci (vs. absent in A. anaemariae, A. anomala, A. bilabialata, A. brevis, A. carli, A. crisae, A. darwini, A. heterozonata, A. hiata, A. leeseri, A. lumbricalis and A. mitchelli). Additionally, Amphisbaena filiformis differs from other species two-pored by having head slightly thiner than trunk (vs. strongly smaller in A. absaberi, A. carli, A. cuiabana and A. roberti); autotomic site between 9–10th caudal annuli (vs. between 3–4th in A. anomala, 4–6th in A. neglecta and A. silvestrii; 6–8th in A. bilabialata and A. persephone, 6–7th in A. mitchelli; and 7–8th in A. miringoera and A. roberti); tail tip slightly compressed (vs. rounded in A. anaemariae, A. anomala, A. brevis, A. caiari, A. carli, A. crisae, A. darwini, A. dubia, A. heterozonata, A. hiata, A. leeseri, A. lumbricalis, A. miringoera, A. mitchelli, A. neglecta and A. silvestrii; and hardly compressed A. absaberi, A. bilabialata, A. cuiabana and A. roberti); and postmalar row absent (vs. present in A. carli, A. darwini, A. heterozonata, A. hiata, A. leeseri and A. silvestrii) (Ribeiro et al. 2016).
|Comment||Habitat: sandy soil, among open lowland rainforest, locally characterized by the babaçu palm tree.|
Morphology: This species is one of ~20 species of Amphisbaena with two precloacal pores (Ribeiro et al. 2019).
|Etymology||The specific epithet filiformis is formed from the Latin words filum (= thread) and forma (= shape) in reference to the slender body shape characteristic of the new species.|