Amphisbaena filiformis, Ribeiro, Síria, Gomes, Jerriane O., Silva, Helder Lúcio Rodrigues Da, Cintra, Carlos Eduardo D. & Jr, Nelson Jorge Da Silva, 2016

Ribeiro, Síria, Gomes, Jerriane O., Silva, Helder Lúcio Rodrigues Da, Cintra, Carlos Eduardo D. & Jr, Nelson Jorge Da Silva, 2016, A new two-pored species of Amphisbaena (Squamata, Amphisbaenidae) from the Brazilian Cerrado, with a key to the two-pored species of Amphisbaena, Zootaxa 4147 (2), pp. 124-142 : 125-134

Amphisbaena filiformis sp. nov.

( Figs. 2–6 )

Holotype. MPEG 27916 (field number: EDR 730), an adult male from municipality of Babaçulândia (07o14’45” S, 47o46’38” W, 156 m), State of Tocantins, Brazil, collected on 0 1 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 0 8 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. (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 chevronshaped 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.

miđbođy half-annulus; DSc đorsal succi; IL infralabials; LC lateral of cloaca; LS lateral succi; MH međiam hiatos; NS nasals suture; P present; PCL precloacal pores;

present incomplete; PML postmalar row; S Snout in đorsal view; TA tail annuli; TAC tail autotomic constriction; TT tail tip; R rounđeđ; SL supralabials; SC slightly convex; SCp slightly compresseđ; VS ventral segments in miđbođy half-annulus; VSc ventral succi. References (Ref.): 1 Present stuđy; 2 Strüssmann & Carvalho 2001); 3 Vanzolini (1997); 4 Gans (1971a); 5 Mott et al. 2008; 6 Strüssmann & Mott (2009); 7 Teixeira et al. (2014); 8 Pinna et al. (2010); 9 Strüssmann & Carvalho 2001); 10 Strüssmann & Mott (2009); 11 Perez et al. (2012); 12 Gans (1964a); 13 Montero & Céspeđez (2002); 14 Gans (1964b); 15 Vanzolini (1996); 16 Vanzolini 1971); 17 Mott et al. (2011); 18 Gans (1964đ); 19 Gans (1962b); 20 Pinna et al. (2014); 21 Gans (1964c); anđ 22 Gans (1962b). Diagnostic characters are given in bolđ.

Comparison With Others South American Amphisbaenians Species. 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 ).

Description of the holotype ( Fig. 2 ). A small for mediam amphisbaenian, snout-vent length 193 mm, tail length 17 mm; and midbody diameter 4 mm (2.1% of snout-vent length). Head relatively small (2.3% of snout-vent length), rounded and not distinct from the neck; rostrum rounded, projecting forward beyond the jaw (prognathous snout).

Rostral visible in dorsal view ( Fig. 2 A), subtriangular in ventral view ( Fig. 2 C), lateral border concave, in contact with nasals anterolaterally and first supralabials latero-posteriorly. Nasals quadrangular, paired, with a long middorsal suture (suture length ca. 17% of head length), posterior border concave, in contact with the rostral, the first and second supralabials, and the prefrontals posteriorly. Nostril near the antero-inferior angle of the nasal shield ( Fig. 2 ). Prefrontals roughly trapezoid, paired, with a long middorsal suture (suture length ca. 29 % of head length), longer than the nasal middorsal suture, shorter than the frontal middorsal suture (suture length ca. 40% of head length), anterior border convex, latero-posterior portion projected, in contact with nasals, second supralabials, oculars and frontals. Frontals irregularly polygonal, paired, with a long middorsal suture, elongated (length 2.1 times width), in point contact with ocular, in contact with postoculars, prefrontals and parietals. Parietals irregularly polygonal, paired, with a short middorsal suture, almost as long as wide, with their posterior border straight and parallel to the second body annulus, in contact with frontal anteriorly, postocular laterally, and second body annulus posteriorly. The anterior edge of the parietals is at the level of the angulus oris. Body annulus behind parietals shows regular middorsal scales ( Fig. 2 A).

Oculars diamond-shaped, relatively long (length representing ca. 33% of head length), in broad contact with second and third supralabials, prefrontals and postoculars, in point contact with frontals and temporals posteriorly. Eyes visible located in central part of oculars. Postoculars pentagonal, relatively long (length. 34% of head length), longer than high, in contact with oculars anteriorly, in dorsal contact with frontals and parietals, in ventral contact with temporals, with their posterior border straight and parallel to the second body annulus posteriorly ( Fig. 2 B). Three supralabials, irregularly polygonal; first rhomboid, smallest, longer than high, in contact with rostral, second supralabials and in extensive upper contact with the nasals; second supralabials relatively high and narrow, forming an oblique (leaning anteriorly) irregular rectangle, ca. 50% higher than length, in point contact with nasals, in contact with frontals, oculars, first and third supralabials; third supralabials pentagonal, almost as high as wide, in contact with second supralabials, oculars, temporals and postsupralabials. Posteriorly of the supralabials there is a row of scales that includes postoculars, temporals and postsupralabials. Temporals smaller than postoculars, limited for second body annuli posteriorly, in point contact with oculars, in upper contact with the postoculars and with the upper part of the 3rd supralabials, in lower contact with postsupralabials.

Three infralabials, firsts roughly triangular, in point contact with postmental in broad contact with the mental and the second infralabials. Second infralabials irregularly polygonal, being the largest shield of the chin (length representing ca. 26% of head length), longer than high, with posterior portion projected, in point contact with first row of postgenials and preventing contact between postmental and malars, in broad contact with postmental, malar and first and third infralabials. Third infralabials the smallest, nearly rectangular, in broad contact with second infralabials, malar and first body annulus. Behind the third infralabial a slightly enlarged scale of first body annulus (behind angulus oris) appears to continue the infralabial series. Mental rectangular, anteriorly abruptly widening, only slightly larger than the postmental, lateral borders straight, in broad contact with postmental and the first infralabials. Postmental single, pentagonal, in point contact with first infralabial, in broad contact with mental anteriorly, second infralabial laterally, and first row of postgenials posteriorly. Two rows of postgenials; first with two distinctly larger scales and one smaller, in point contact with second infralabials, in broad contact with postmental anteriorly, malars laterally, and with the second postgenial row posteriorly; second postgenial row with five irregularly polygonal equally sized shields, in broad contact with first row of postgenials anteriorly, malars laterally and first body annuli posteriorly. Two malars, one on each side, irregularly polygonal, in broad contact with second infralabial anteriorly, third infralabial and two rows of postgenials laterally, and the fisrt body annulus posteriorly. Postmalar row absent.

Body annuli distinct. The first half-annulus ventral is composed for eleven shields and dorsally the first halfannulus includes postsupralabial, temporal and the very large postocular dorsally limited by frontal and parietal. Body annuli 336, one intercalated incomplete annulus in the 334 body annulus (not included in the counts), with ventral part missing. Three lateral annuli in the cloacal region. Thirteen (6 rigth + 7 left) dorsal segments per midbody annulus; 14 ventral segments per midbody annulus; ventral segments with two central scales larger than adjacent scales and, only these, slightly larger than dorsal scales. Lateral and dorsal sulci clearly marked ( Fig. 3 ). Lateral sulci well marked and apparent from the 48th body annulus until almost to level of cloaca. Dorsal sulci apparent from the 92th body annulus until almost to tip of tail. No ventral sulci. Two elongate oval precloacals pores in two adjacent central scales of the precloacal shield. Cloacal segments regular, eight precloacal and 14 postcloacal segments. Twenty two caudal annuli; tenth tail annulus is slightly narrowed, it may correspond an autotomic site ( Fig. 4 ; see discussion in Gomes & Maciel 2012). Besides that present more heavily pigmented ventral scales (relative to other tail scales). Tip of tail shows a compression into a vertical keel ( Fig. 5 ).

Color in life ( Fig. 6 ). Overall color pattern spinel red (108B). The cephalic shields rose pink (108D) from rostral to edge of frontal. The dorsum presents regularly distributed the center of scale brick red (132A), with spinel pink (108C) lateral borders, apparent from the 46th body annulus to tip of tail. Ventral segments, below lateral sulci, rose pink (108D).

Color in preservative (based on the type-series). The specimens have a range of dorsal pigmentation of cream (54) to lighter cream on dorsal and ventral region. On dorsum, the center of segments are ground cinnamon (239).

Variation. There is little meristic and morphometric variation, the most relevant of which is shown in Table 2 . Additionally, in the paratypes MPEG 27915, MPEG 27917 and MPEG 27919 postmental and malars are in contact. In MPEG 27919 mental and second infralabials are in contact. Parietals in MPEG 27917 posteriorly interrupting the first body annulus and reaching the second body annulus; the second postgenial row on the left side, reaches beyond the third infralabials.

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.

Distribution and habitat. Amphisbaena filiformis has been collected only in Babaçulândia and Estreito municipalities, States of Tocantins and Maranhão, respectively, in the northern Brazilian Cerrado ( Fig. 1 ). The specimens from Babaçulândia municipality were collected in the left margin of the Corrente river, and the specimens from Estreito municipality were collected in the right margin of the Tocantins river on sandy soil. Babaçulândia and Estreito municipalities are located in a complex phytogeographic region, with three distinct vegetational formations: open lowland rainforest (floresta ombrófila aberta de terras baixas), seasonal forest (floresta estacional), and Cerrado. However, on the margins of Corrente river and Tocantins river, the main vegetational formation is the open lowland rainforest, locally characterized by the babaçu palm tree ( Attalea speciosa Mart. ex. Spreng). The large presence of this species in a region is known as "palm forest" ( Fig. 7 ) ( IBGE 1992). It was in this vegetation that the specimens of A. filiformis were found.

Figures

FIGURE 1. Geographic distribution of Amphisbaena filiformis sp. nov. from Brazilian Cerrado. Red star represents distribution of paratypes in the right bank of Tocantins River, Estreito municipality, State of Maranhão. Red star with a black central dot represents type-locality in the left bank of Tocantins River, Babaçulândia municipality, State of Tocantins; Brazil.

FIGURE 2. Dorsal (A), lateral (B) and ventral (C) views of the head of Amphisbaena filiformis sp. nov. holotype (MPEG 27916).

FIGURE 3. Dorsal view of midbody annulus of Amphisbaena filiformis sp. nov. (MPEG 27918). The arrow points to the lateral (1 and 3) and dorsal (2) sulci.

FIGURE 4. Ventral view of cloacal region of Amphisbaena filiformis sp. nov. (MPEG 27919). The arrow points to the autotomic annulus.

FIGURE 5. Oblique view of the tail of Amphisbaena filiformis sp. nov. (MPEG 27919). Note the vertical keel of the extreme tip.

FIGURE 6. Amphisbaena filiformis sp. nov. in life (not identified specimen of type series) from Babaçulândia municipality, State of Tocantins, Brazil. Photo by C. E. D. Cintra.

FIGURE 7. “ Floresta Ombrófila Aberta das Terras Baixas ” with palm tree forest in center, municipality of Babaçulândia, State of Tocantins, where the holotype of Amphisbaena filiformis sp. nov. was collected.

Tables

TABLE 2. Variation in meristic and morphometric (mm) characters for the type series of Amphisbaena filiformis sp. nov. from Babaçulândia (MPEG), State of Tocantins, and from Estreito (MZUSP), State of Maranhão, Brazil. (*) holotype. F = female, M = male and N / A = not available.

	*MPEG	MPEG	MPEG	MPEG	MPEG	MZUSP
Variables	27916	27915	27917	27918	27919	102044
Sex	M	N/A	M	N/A	N/A	M
Body annuli	336	335	328	329	332	341
Caudal annuli	22	10+x	22	23	22	23
Dorsal segments	6+7	6+6	7+7	6,7+6	6+6	7+7
Ventral segments	14	14	14	14	14	14
Ventral sulcus	Absent	Absent	Absent	Absent	Absent	Absent
Postgenials	2+5	3+5	2+6	3+5	2+5	2+4
Laterals	3	3	4	4	3	2
Autotomic annulus	10	10	10	10	10	10
Snout–vent length	193	217	193	216	187	212
Tail length	17	8.2+x	17.7	17.8	14.5	19.2
Head length	4.5	5	4.8	5	4.3	4.2
Head width	2.5	2.7	3	2.8	2.5	2.7
Body width at midbody	4	3.9	3.7	3.9	3.6	3.1
continued.