Amphisbaena hoogmoedi, Oliveira & Vaz-Silva & Santos-Jr & Graboski & Jr & Vechio & Ribeiro, 2018

Oliveira, Elaine C. S., Vaz-Silva, Wilian, Santos-Jr, Alfredo P., Graboski, Roberta, Jr, Mauro Teixeira, Vechio, Francisco Dal & Ribeiro, Síria, 2018, A new four-pored Amphisbaena Linnaeus, 1758 (Amphisbaenia, Amphisbaenidae) from Brazilian Amazon, Zootaxa 4420 (4), pp. 451-474 : 453-462

Amphisbaena hoogmoedi sp. nov.

( Figs. 1–3 )

Holotype. MZUSP 106219 (field number CHTP 13677), adult female, from right bank of Teles Pires River (- 9.352°S - 56.692° W, 220 m a.s.l.; datum WGS 84), area impacted by the Teles Pires hydroelectric dam, Jacareacanga municipality, Pará, Brazil, collected on 23rd September 2014 by faunal rescue team of Arcadis-Logos.

Paratypes. All collected at type locality by faunal rescue team of Arcadis-Logos. MPEG 32283 (field number CHTP 13670), female collected on 29rd September 2014; MPEG 32284 (field number CHTP 13672), male collected on 23rd September 2014; MZUSP 106220 (field number CHTP 13683), male collected on 23rd September 2014; MPEG 32285 (field number CHTP 13759), male collected on 30rd September 2014.

Diagnosis. Amphisbaena hoogmoedi sp. nov. is a medium-sized amphisbaenid (291 mm maximum snout-vent length), and can be distinguished from its congeners by the following combination of characters (see details in Appendix II): (1) snout convex in profile view, sligthly compressed not keeled; (2) pectoral scales arranged in regular annuli; (3) conspicuous autotomic site between 7th–8th caudal annuli; (4) 247–252 dorsal half-annuli; (5) 27 caudal annuli; (6) tail length representing 9.5–10.4% of snout-vent length; (7) four precloacal pores arranged in sequence, (8) three supralabials, (9) a rounded tail, (10) 22–24 dorsal segments in midbody half-annulus; (11) postmalar row absent; (12) head length 2.1–2.9% of snout-vent length; (13) prefrontals length 46.6–49.5% of head length; (14) prefrontals suture length 38–44.6% of head length; (15) small malar length 10.6–13.4% of head length; (16) second infralabial length 33.8–38.5% of head length; (17) ventral length of head 2.7–2.9% of snout-vent length; (18) mouth length 80.2–81.8% of head length; (19) third infralabial length 16.4–19.6% of head length; (20) snout length 62.5–78.6% of head length; (21) ocular length 23.4–26.2% of head length; (22) mental length 23.2–25.4% of head length; (23) postmental length 27.2–31.3% of head length; (24) frontals suture length 23.4–32.3% of head length; (25) postocular width 25–31.9% of maximun width of head; (26) first supralabial length 24.9–30.6% of head length; (27) second supralabial length 27.7–30% of head length; and (28) second supralabial height 26.9–28.8% of maximun head height.

Comparisons with other species. Amphisbaena sp. nov. is diagnosed of all other South American amphisbaenians by combination of characters. Differs from Amphisbaena acrobeles ( Ribeiro, Castro-Mello & Nogueira, 2009) , A. bilabialata ( Stimson, 1972) , A. kingii ( Bell, 1833) , A. anomala ( Barbour, 1914) , Mesobaena huebneri Mertens, 1925 ; M. rhachicephala Hoogmoed, Pinto, Rocha & Pereira, 2009 ; and all Leposternon species, mainly in having the snout convex in profile view, sligthly compressed not keeled (vs. snout hardly compressed forming a sharp and prominent keel or snout depressed shovel-like). Differs from A. anomala and all Leposternon species by having pectoral scales arranged in regular annuli (vs. pectoral scales with an irregular form, and dermal annuli not regularly arranged).

Amphisbaena sp. nov. differs all other South American amphisbaenians, except A. absaberi , A. arenaria , A. bahiana , A. bedai , A. borelli , A. brasiliana , A. carli , A. cuiabana , A. ignatiana , A. kraoh , A. roberti , A. saxosa , and A. steindachneri (Appendix II), mainly in having snout slightly compressed not keeled (vs. snout not compressed and rounded). Differs from A. bahiana , A. brasiliana , A. carli , A. kraoh , and A. saxosa mainly by having 247–252 dorsal half-annuli, 27 caudal annuli and a tail length representing 9.5–10.4% of to snout-vent length (vs. less than 247 or more than 252 dorsal half-annuli, less than 27 caudal annuli and less than 9.5). Differs from Amphisbaena absaberi in having 247–252 dorsal half-annuli, four precloacal pores arranged in sequence, and conspicuous autotomic site between 7th–8th caudal annuli (vs. 239–242 dorsal half-annuli, two precloacal pores separated by cloacal segments, and autotomic site between 5th–6th caudal annuli), head length 2.1–2.9% of snout-vent length (vs. 3.2–4.2%). Differs from Amphisbaena arenaria and A. bedai in having four precloacal pores arranged in sequence and three supralabials (vs. two pairs of pre-cloacal pores separated by two medial segments extending from the cloacal plate and four supralabials). Differs from A. borelli , A. roberti and A. steindachneri in having a rounded tail and 22–24 dorsal segments at midbody (vs. a keeled tail tip and less than 20 dorsal segments at midbody). Differs from A. cuiabana and A. ignatiana mainly in having 247–252 dorsal half-annuli, 27 tail annuli (vs. 278–309 and 15–20, and 255–263 and 15–20, respectively), prefrontals length 46.6–49.5% of head length (vs. 36.7–45% and 32,7%, respectively), prefrontals suture length 38–44.6% of head length (vs. 30.5–36.7% and 30%, respectively), small malar length 10.6–13.4% of ventral length of head (vs. 1.1–8.3% and 4.5%, respectively), second infralabial length 33.8–38.5% of head length (vs. 11–32% and 26.3%, respectively). In addition, it differs from A. cuiabana mainly in having ventral length of head 2.7–2.9% of snout-vent length (vs. 1.8–2.5%), mouth length 80.2–81.8% of head length (vs. 57.9–65.4%), and third infralabial length 16.4–19.6% of head length (vs. 6.8–12%). Differs from A. ignatiana mainly in having four precloacal pores, three supralabials and postmalar row absent (vs. six precloacal pores, four supralabials and postmalar row present), snout length 62.5–78.6% of head length (vs. 51%), ocular length 23.4–26.2% of head length (vs. 46.5%), mental length 23.2–25.4% of ventral length of head (vs. 19.5%), postmental length 27.2–31.3% of ventral length of head (vs. 19.5%), frontals suture length 23.4–32.3% of head length (vs. 36.4%), tail length 9.5–10.4% of snout-vent length (vs. 11.6%), postocular width 25–31.9% of maximun width of head (vs. 34.7%), first supralabial length 24.9–30.6% of head length (vs. 19.7%), second supralabial length 27.7–30% of head length (vs. 13.3%) and second supralabial height 26.9–28.8% of maximun head height (vs. 39.6%).

Description of the holotype: medium-sized specimen; snout-vent length 205 mm; tail length 21.2 mm. Head slightly compressed, not keeled, convex in profile, somewhat distinct from neck, which is slightly narrower than the body; snout prognathous. Rostral campaniform and visible in ventral view, higher than wide, in contact with nasal, in narrow contact with first supralabial; nasals aligned at the midline, subrectangular, longer than wide, in broad contact with each other at the midline, in broad contact with prefrontal and first supralabial, with nostrils placed on the anterior and ventral half of the scale; prefrontals paired, aligned at the midline, subpentagonal in profile, longer than wide, in broad contact at midline, in narrow contact with the first supralabial, and in broad contact with the second supralabials, frontal, and ocular, is the larger shield on top of the head; frontals paired, aligned at the midline, in narrow contact with post-oculars laterally, and contacting with parietals; occipitals absent; parietals in four subquadrangular segments, followed by the first dorsal half-annulus; oculars longer than high, subtrapezoidal, in contact with second and third supralabials, postocular, and prefrontal, and in point contact with temporal; eyes not visible; postocular longer than wide, subpentagonal, in contact with frontal temporal, parietal and the segments of the first dorsal half-annulus, and in point contact with prefrontal; temporal small, subtriangular, in contact with the third supralabial and the first dorsal half-annulus; three supralabials, the first and second longer than wide; first supralabial subtrapezoidal, contacting second supralabial; second supralabial subpentagonal, contacting with third supralabial; third supralabial subpentagonal, in contact with the segments of the first dorsal half-annulus.

Mental longer than wide, in contact with the first pair of infralabials and postmental; postmental longer than wide, in contact with the second supralabial and the first row of postgenials; first row of postgenials with six shields irregularly distributed, in contact with malars and the second row of postgenials; the second row of postgenials with seven elongated and narrowed shaped shields, in contact with the malars and the first ventral halfannulus; one malar on each side, wider than long, in contact with second, third infralabial and the first ventral halfannulus. Three infralabials, first medium sized, subpentagonal, in contact with second supralabial, the second the largest, subhexagonal, in contact with third infralabial; third infralabial smallest, longer than wide, in contact with the first ventral half-annulus.

Body annuli well demarcated, first and second annuli without enlarged dorsal segments. Segments become regularly rectangular toward posterior portion of body and progressively longer than wide, and smaller in size, and larger towards midventral areas; 249 dorsal annuli; 27 caudal annuli; tail long with autotomy line on the seventh annulus; four lateral half-annuli adjacent to cloacal region, between the last body annulus and the first caudal annulus; lateral sulci clearly visible; 23/20 dorsal and ventral segments at midbody, respectively; dorsal and ventral sulci absent; cloacal plate with ten segments increasing in size from towards midline, twelve post-cloacal segments; four precloacal pores strongly visible on the row of segments on the last ventral half-annulus; each pore placed on the posterior half of a single segment, and distributed along a continuous series of segments, but pores in the medial scales placed laterally.

Coloration light brown on dorsal half-annuli and on the lateral sulcus. On the ventral portion of the body and head is light beige. The infralabial shield and shields on the side and back of the head are yellowish ( Figs. 1–3 ). The coloration on the tail follows that on the back, with the last caudal annulus light brown both dorsally and ventrally ( Fig. 3 ).

Cranial osteology ( Figs. 4–5 ). Description based on a single specimen (holotype, MZUSP 106219) Postorbital region elongate, approximately 70% of skull length, slightly concave dorsally, preorbital region shorter, 30% of skull length, craniofacial angulation slight, ca. 160º (sensu Kearney 2003); skull length approximately 11 mm, from tip of premaxilla to the occipital condyle, 5% of snout-vent length; prognathous. Dorsal surfaces smooth, nasal/frontal region rugose. Orbit delimited by posterior portion of prefrontal, lateral portion of the frontal, and tabulosphenoid, and the dorsal margin of the ectopterygoid, bordered ventrally by posterior process of maxilla.

Premaxilla and nasals form a rounded, slightly acuminate, snout in dorsal view and oblique in profile. Premaxilla, maxillae and nasals enclose the border of a relatively large external nasal opening. Premaxilla, azygous, longer than wide, slender; contacts maxilla ventrolaterally, nasal laterally, septomaxilla ventromedially; nasal process long, narrow, projects between nasals, reaching as far as 70% of nasal length; palatal process wide, roughly triangular in ventral view, curve in profile, concave and notched posteriorly; overlays maxillary palatal plate posteroventrally, anteriorly to maxillary teeth; anterior opening of the longitudinal canal posteriorlly from anterior contact between premaxilla and nasal; bears seven teeth, three medials, anterior one largest, projects posteroventrally; a short diastema present between anterior-most maxillary tooth and posterior premaxillary tooth. Nasal, paired, longer than wide, concave ventrally, with complex shape, anterior margin convex, projecting anteromedially, posterior margin with a long, narrow fingers projected posteriorly; dorsal surface pierced by several small foramina, communicating to a posterolateral canal opening in the nasal chamber; contacts maxilla laterally, frontal posteriorly, premaxilla medially, septomaxilla anteroventrally. Maxilla, paired, longer than wide and high, with a complex shape; contacts nasal frontal anterodorsally and prefrontal dorsally, premaxilla anteroventrally, ectopterygoid posteroventrally, vomer medially, palatine posteriorlly, septomaxilla dorsomedially; frontal process relatively long, composed of a single ramus, inserted between anterior finger of frontal, and prefrontal; premaxillary process flat; lateral plate flat, slightly concave, pierced by five foramina; palatal plate roughly longitudinally concave, receiving the anteromedial process of ectopterygoid; four teeth in each maxilla, first largest, fifth smaller.

Palatal series of difficult visualization due to the presence of debris inside the animal’s mouth. Septomaxilla, paired, robust, longer than wide and high; contacts anteriorly premaxilla and nasal, ventromedially vomer, ventrolaterally maxilla; lateral process relatively short; vertical plate concave ventrally; horizontal plate wide, overlaying palatal plate of maxilla. Vomer, paired, longer than wide and high; contacts anteriorly premaxilla, laterally maxilla, posteriorly palatine, dorsally septomaxilla; rostral process slightly curved ventrally, posterior process elongate, narrow, ending in an acute posterior tip, ventrally to palatines, and anteriorly to the cultriform process of the parabasisphenoid, separated at midline by a pyriform recess; lateral wing, projects posterodorsally a wide process, delimiting – between it and the medial articular plane—a groove that receives vomerine process of palatine, and anterodorsally a short roughly round process that delimits, between it and the medial articular plane, a posterior concave wall of vomeronasal chamber. Palatine, paired, longer than wide and high, contributes to the floor and medial wall of orbit, medial, dorsal and lateral walls of choanal vault, its posterior opening relatively large; contacts ectopterygoid laterally, pterygoid posteriorly, vomer anteroventrally; vomerine process narrow, acute, projects anteromedially; pterygoid process wide, rounded; medial surface of palatine arched, forming the posterodorsal border of the internal choana. Ectopterygoid, paired, longer than wide, placed between maxilla and pterygoid; contacts pterygoid posteriorly, palatine medially, maxilla anterodorsally, medially to the two posterior maxillary teeth; posteroventral process long, acute, contacts palatine medially and pterygoid posteriorly; posterodorsal process, elongate, contacts pterygoid posterolaterally; anterolateral process wide, rounded, contacts posterior end of maxillary lateral plate; anteromedial process elongate, contacts palatal plate of maxilla ventrally. Pterygoid, paired, longer than wide and high, narrower posteriorly, borders ventrolaterally the surface of the skull; contacts maxilla, palatine and ectopterygoid anteriorly, parabasisphenoid medially, quadrate dorsolaterally; posterior process long, curved dorsally, contacts quadrate; anterolateral process wide, three-ramified, lateral ramus wider, contacting ectopterygoid anteriorly, palatine medially, a lateral ridge projects dorsally along its length; anteromedial process elongated, curved laterally, ending in an acute tip inserted between palatine and cultriform process of parabasisphenoid.

Intermediated segments composed of frontals, prefrontals, parietal and tabulosphenoid. Prefrontal, paired, higher and wide and long, large, roughly triangular in lateral view, contributes to facial surface and inner wall of orbit; contacts maxilla ventrally, frontal medially and posteriorly, palatine posteroventrally. Frontal, paired, longer than wide, with a complex shape, and in contact at is midline by sinusoidal suture; contacts parietal posteriorly and nasal anteriorly both through interdigitate sutures, maxilla and prefrontal lateroventrally, tabulosphenoid posteroventrally; posterior fingers long, narrow, irregularly in size, project in its suture with parietal; anteromedial finger wide; anterolateral finger deeply bifurcate, producing a suture with three frontal projections indented with two nasal ones; dorsal plate slightly convex, rugose anteriorly, with a somewhat similar texture as the nasals, projecting wide descending process vertical plate in contact at their mid ventral line through the ventral process that overlays ventrally tabulosphenoid, enclosing the anterior portion of cranial cavity, defining an anterior heartshaped oblique aperture; lateral process projecting ventrolaterally from the descending process vertical plate, contacting prefrontal, forming the anterior wall of orbit. Parietal, azygous, longer than wide and high; contacts frontal anteriorly, projecting irregular fingers into the interdigitate suture with frontal, tabulosphenoid lateroventrally, supraoccipital posteriorly, posterolaterally alar process of prootic externally, oticoccipital complex internally, posterior notch receiving ascendens process of supraoccipital; sagittal crest well marked, running along middorsal line from the contact with ascendens process of supraoccipital to its contact with frontal; lateral external walls broad, convex, reaches but not contributes to the border of the Gasserian foramen; contributes to the lateral walls and roof of cranial cavity. Tabulosphenoid azygous, slightly longer than wide; contacts anterodorsally frontals, anterolaterally parietal, posteroventrally parabasisphenoid, ventrally palatine, posterolaterally alar process of prootic; half of its lateral edge free, delimiting the anteromedial border of about 30% of the length of Gasserian foramen; anteromedial process wide, notched medially, receiving and underlapping medial plate of frontals, anterolateral process wide, half of tabulosphenoid length, curved posteriorly; posterolateral process notched medially receiving a long, but shallow dorsal projection of cultriform process of parabasisphenoid, delimiting ventrally a groove that receives the cultriform process of parabasisphenoid.

Occipital segment composed of elements-X, parabasisphenoid, quadrates and the co-ossified supraoccipital, exoccipital, basiocciptal and otic capsules. Element-x elongate, anterior portion rounded, its suture with basioccipital and parabasisphenoid well-marked, placed anteroventrally to fenestra ovale. Parabasisphenoid azygous, longer than wide, narrower anteriorly; approximates anterolaterally pterygoid, contacts anterodorsally tabulosphenoid, posterolaterally element-x and posteriorly basiocciptal; sella turcica shallow, flat, delimited laterally by a low wall, which contributes to about 60% of Gasserian foramen, pierced posteroventrally by the internal carotid foramen; basipterygoid process not distinct. Quadrate paired, longer than wide, ca. 50% mandible length, wider posteriorly, roughly straight; contacts extracolumella ventrolaterally, quadrate process of the pterygoid ventromedially, compound bone of mandible anteriorly, paroccipital process of occipital complex posteriorly; cephalic condyle slightly concave posteriorly, defining a shallow glenoid fossa, articulates with paraoccipital process of occipital complex posteriorly, mandibular condyle articulates with the compound bone of mandible anteriorly. Supraoccipital, basioccipital and exoccipital fused, placed posteriorly in the skull, at its widest portion. Occipital crest wide, indented posteriorly, dorsally to foramen magnum; ascendens process of supraoccipital narrow, projects anteriorly; paroccipital process, robust, projects lateroventrally, partially encloses columella anterodorsally. Basiocciptal plate convex posteriorly, slightly convex ventrally, contacting parabasisphenoid anteriorly, anterolaterally element-x, via anterolateral process; anterolateral process and paroccipital process delimiting fenestra ovale; alar process of the prootic long, slightly curved medially, contributes to the posterior 70% of Gasserian foramen length. Occipital condyle formed by posterior portions of basioccipital and exoccipital bones, bicipital, connects to the basioccipital plate through a rather wide neck; large hypoglossal foramen placed laterally to occipital condyles. Foramen magnum, as wide as occipital condyle, bordered by fused exoccipital and supraoccipital.

Auditory apparatus composed of extracolumella and columella. Extracolumella, paired, longer than wide, slender, extending anteriorly from the stapedial shaft across the lateral face of quadrate, attaching to soft tissue along the mandible, ending anteriorly to the level of the anterolateral end of the compound bone of mandible; contacts columella posteriorly, quadrate medially. Columella paired, robust, longer than wide and high; shaft relatively short; footplate concave, fills fenestra ovale, partially covered by paroccipital process; anterior process relatively long, acute.

Mandible composed of dentary, angular, coronoid and compound bones. Dentary longer than wide and high, narrower anteriorly; contacts compound bone posteriorly, medially and laterally, angular ventromedially, coronoid posterodorsally, bears seven teeth slightly recurved, second and third largest, three labial foramina, first at the level of second tooth, second at the level of intervening specie between third and fourth teeth, third at the level of sixth tooth; posterodorsal process oblique, long, narrows toward its end; posteroventral process straight, forms occupies about 40% of mandibular ventral surface. Coronoid flat, higher than wide and long; anteromedial process relatively long, projects over medial surface of dentary and compound bone, not contributing to the medial wall of Meckel’s canal. Angular elongate, contributes to ventromedial surface of mandible, reaching anteriorly to the level of anterior tip of anteromedial process of coronoid. Compound bone with complex shape, covers posterolateral and ventromedial surfaces of mandible, pierced by two lateral foramina; anteroventral process relatively long, projects along lateral wall of Meckel’s canal internally to dentary; articular process delimiting ventrally the glenoid fossa; Meckel’s canal runs along entire length of mandible, anterior and posterior foramina relatively wide.

Intraspecific variation. The main variations in the series-type for meristic and morphometric data is given in Table 1. Variation in the arrangement and contact of shields were also observed. Specimen MPEG 32284 had no temporal on the left side of the head, with a very large post-ocular which may be fused with temporal; this also resulted in changes in the contact patterns of cephalic shields on the left side of this specimen; this specimen also had a segment separating the precloacal pores into two pairs. All paratypes have ocular scales with visible eyes, which is missing in the holotype.

Hemipenis (MZUSP 106220 – Paratype) ( Fig. 6 ). Bilobed with capitate apex and lamellae on the side of the lobes, which are more visible on the sulcate side of each lobe. The spermatic groove is positioned centrally, is bifurcated at the base of the lobes in its most distal part, with each branch extending to the apexes. Each lobe is equivalent to 33% of the size of the hemipenis body. The absulcate side is more prominent than the sulcate, and exhibits a small accumulation of tissue at the distal end of the body of the hemipenis.

Etymology. Amphisbaena hoogmoedi sp. nov. is named in honor of Dr. Marinus S. Hoogmoed (National Natuurhistorisch Museum, Leiden, the Netherlands, currently at the Goeldi Museum, Belém, Pará, Brazil), for his contribution to the knowledge of the Neotropical herpetofauna especially to the amphisbaenian taxonomy.

Distribution and habitat. Amphisbaena hoogmoedi sp. nov. is known so far only for the type locality in Jacareacanga municipality, on the right bank of the Teles Pires River, State of Pará, Brazil ( Figs. 7 and 8 ). According to WWF (2016), the region covering the area of the Teles Pires hydroelectric power plant consists of Tropical and Subtropical Moist deciduous forests, an eco-region of Tropical Dry Forest with a variety of habitats (alluvial forests and patches of open areas). The new species was collected in the Rain Forest Submontane, Rain Forest Alluvial, and semideciduous forest Submontane.

Figures

FIGURE 1. Amphisbaena hoogmoedi sp. nov. (holotype, MZUSP 106219). (A) Dorsal and (B) general ventral view. Scale bar = 20 mm.

FIGURE 2. Amphisbaena hoogmoedi sp. nov. (holotype, MZUSP 106219). (A) Dorsal, (B) lateral, and (C) ventral view of head. Scale bar = 2 mm.

FIGURE 3. Tail of Amphisbaena hoogmoedi sp. nov. (holotype, MZUSP 106219). White arrow indicates the position of the line of caudal autotomy. Scale = 20 mm.

FIGURE 4. Dorsal (top), lateral (middle) and ventral (bottom) views of the skull of Amphisbaena hoogmoedi sp. nov. (holotype, MZUSP 106219). app = apical process of parietal; an = angular; apsoc = ascendens process of supraoccipital; bh = basihyal; bo = basioccipital; cb1 = 1st ceratobranchial; cb2 = 2nd ceratobranchial; cpb = compound bone; co = columella; cp = choanal process; cr = coronoid; d = dentary; ecp = ectopterygoid; exc = extracolumella; f = frontal; Gf = Gasserian foramen; jf = jugal foramen; lc = longitudinal canal; m = maxilla; n = nasal; nf = nasal foramina; occ = occipital condyle; p = parietal; pbs = parabasisphenoid; pl = palatine; pm = premaxilla; pop = paroccipital process; prf = prefrontal; pt = pterygoid; pyr = piriform recess; q = quadrate; sa = suprangular; soc = supraoccipital; ts = tabulosphenoid; v = vomer; x = element-x.

FIGURE 5. Sagital (top), coronal superior (middle), and inferior (bottom) views of the skull of Amphisbaena hoogmoedi sp. nov. (holotype, MZUSP 106219). an = angular; appo = alar process of prootic; bo = basiocciptal; cl = columella; cpb = compound bone; cr = coronoid; d = dentary; ec = extracolumella; ecp = ectopterygoid; f = frontal; fvn = fenestra vomeronasalis; Gf = Gasserian foramen; jf = julgal foramen; lc = longitudinal canal; m = maxilla; Mg = Meckel’s groove; n = nasal; occ = occipital condyle; otc = otic capsule; pbs = parabasisphenoid; pl = palatine; pm = premaxilla; prf = prefrontal; pt = pterygoid; q = quadrate; scc = semi-circular canals; sm = septomaxilla; st = statolit; ts = tabulosphenoid; v = vomer; x = element-x.

FIGURE 6. Hemipenis of Amphisbaena hoogmoedi sp. nov. (paratype, MZUSP 106220): A) Sulcate side, B) Close-up of lobes on the sulcate side, C) Upper view of lobes, D) Absulcate side e E) Lateral view of hemipenis. Scale = 2 mm.

FIGURE 7. Geographic distribution of Amphisbaena hoogmoedi sp. nov. (Red dot).

FIGURE 8. Habitat at the shores of Teles Pires River, close to where the specimens of Amphisbaena hoogmoedi sp. nov. were collected.