A century of waiting: description of a new Epictia Gray, 1845 (Serpentes: Leptotyphlopidae) based on specimens housed for more than 100 years in the collection of the Natural History Museum Vienna (NMW)

Epictia rioignis sp. nov. (Figs. 1–15, Table 1)

urn:lsid:zoobank.org:act:4C7CFC14-FDC7-4B41-B7CF-7CCB8F0E8649

Holotype

NMW 15446:6, from Corinto, presumably Nicaragua (12°29′N, 87°11′W, see Discussion for further details) donated by Steindachner in 1907.

Paratypes (7)

NMW 15446:1–5, NMW 15446:7–8 from the type locality, donated by Steindachner in 1907.

Diagnosis

Epictia rioignis sp. nov. can be distinguished from all congeners by the following combination of characters: (1) midbody scale rows 14; (2) midtail scale rows 10; (3) supralabials two, anterior one large and in broad contact with supraocular; (4) infralabials four; (5) subcaudals 14–19; (6) middorsal scale rows 250–267; (7) total number of precloacal vertebrae 231–248; (8) supraocular scales present; (9) frontal scale distinct, not fused with rostral; (10) striped dorsal color pattern with more or less triangular dark blotches on each scale; (11) upper half of eyes visible in dorsal view; (12) some caudals in posterior part of tail are fused in 50% of the specimens; (13) small white blotch in anterior part of dorsal surface of rostral present in about 83% of the specimens; (14) terminal spine and adjacent scales white.

Comparisons

The new species differs from Epictia albipuncta, Epictia striatula, Epictia unicolor and Epictia weyrauchi by having 10 midtail scale rows [vs. 12]. The number of 14 midbody scale rows distinguishes the species from E. undecimstriata [16]. By the presence of an unfused frontal and rostral scale it is differentiated from Epictia ater (including Epictia nasalis), Epictia bakewelli and Epictia schneideri. By having the anterior supralabial in broad contact with the supraocular the new species can be distinguished from E. albipuncta, Epictia amazonica, E. ater, Epictia australis, E. bakewelli, Epictia borapeliotes, Epictia clinorostris, Epictia collaris, Epictia columbi, Epictia diaplocia, Epictia fallax, Epictia goudotii, Epictia magnamaculata, Epictia martinezi, Epictia melanura, Epictia munoai, Epictia pauldwyeri, Epictia peruviana, Epictia phenops, Epictia resetari, E. schneideri, Epictia signata, Epictia subcrotilla, Epictia vellardi, Epictia vindumi, and Epictia wynni [vs. anterior supralabial and supraocular separated by supranasal-ocular contact]. The number of 250–267 middorsal scale rows distinguishes Epictia rioignis sp. nov. from E. albifrons [206–218 sensu Wallach, 2016; 242 sensu Natera Mumaw, Esqueda González & Castelaín Fernández, 2015], Epictia alfredschmidti [267–279], E. amazonica [208–245], Epictia antoniogarciai [195–208], E. collaris [155–166], E. diaplocia [205–233], Epictia hobartsmithi [191–208], E. melanura [395–396], E. munoai [184–226], E. pauldwyeri [202–226], E. peruviana [185–199], E. subcrotilla [318–333], Epictia tenella [215–233 sensu Wallach, 2016 ], Epictia tricolor [276–310], E. unicolor [246], Epictia vanwallachi [188], Epictia venegasi [211–221], and Epictia vonmayi [196–205]. The number of 14–19 subcaudal scales differentiates this species from E. columbi [22–25], E. munoai [10–14], E. nasalis [21], and E. pauldwyeri [10–14]. By the presence of four infralabials [vs. three] Epictia rioignis sp. nov. differs from E. australis, E. borapeliotes, E. collaris, E. munoai, and E. wynni. The presence of a light blotch on the dorsal part of the rostral further differentiates the new species from E. columbi, Epictia rufidorsa, E. vanwallachi, and E. weyrauchi, and the presence of a whitish terminal spine distinguishes it from E. columbi, E. melanura, Epictia melanoterma, E. rufidorsa, and Epictia septemlineata. By lacking a tricolor pattern (reddish-brown, black, yellow) it differs from E. alfredschmidti, Epictia rubrolineata, Epictia teaguei, and E. tricolor. By lacking a preoral groove in the ventral rostral it differs from E. columbi. The presence of a distinct striped dorsal color pattern with more or less triangular dark blotches on each scale distinguishes the new species from E. amazonica [uniformly black coloration, without any trace of stripes], E. ater, and E. columbi [both species appear uniformly dark, pale outline of the scales is only visible upon closer examination]. From Epictia tesselata which is only known from Lima (Peru) and surroundings, the new species differs by having a very small light blotch on the rostral [light spot on the rostral and lower portion of the nasals] and a darker ventral coloration. It differs from E. ater and E. phenops by presenting unfused neural arches of the atlas [vs. fused]. The number of 231–248 trunk vertebrae distinguishes it from E. magnamaculata [199], E. munoai [207], E. phenops [213–246], E. tenella [190–204], and E. tricolor [282].

Description of holotype (Figs. 1 and 2, and upper left picture of Figs. 3–9)

A large specimen with TL of 211 mm; TAL of 10.3 mm; MB of 4.4 mm; MT of 3.1 mm; TL/TAL of 20.5; TL/MB of 48; TAL/MT of 3.3; HW of 2.8 mm; HL of 3.6 mm; HH of 2.3 mm; ED of 0.4 mm; RES of 0.3. Head subcylindrical, slightly dorsoventrally compressed, hardly distinguishable from neck; body cylindrical; not tapered cranially or caudally. Snout rounded in dorsal, lateral and ventral views. Rostral subtrapezoidal in dorsal view with straight apex, straight in ventral view, reaching the imaginary transverse line between the anterior borders of the eyes, contacting upper and lower nasals laterally and frontal dorsally.

Nasal completely divided horizontally by an oblique suture, reaching rostral and first supralabial; ellipsoid nostril located in the center of the suture between upper and lower nasal, having the major axis obliquely oriented along the suture; supranasal higher than wide, contacting rostral anteriorly, infranasal inferiorly, first supralabial and supraocular posteriorly, and frontal dorsally; infranasal not visible in dorsal view, contacting rostral anteriorly and first supralabial posteriorly; two supralabial scales positioned anterior and posterior to ocular scale (1 + 1), respectively, resulting in an upper lip border formed by rostral, infranasal, anterior supralabial, ocular, and posterior supralabial; first supralabial 2.2 times higher than wide, exceeding nostril, reaching central level of eye, dorsally acuminate and in contact with supraocular scale; second supralabial subtrapezoidal 1.3 times higher than wide, slightly exceeding central level of eye, about as high as and at widest point 1.7 times wider than first supralabial; posterior margin of second supralabial in broad contact with temporal and first scale of lateral body row, dorsal margin in contact with parietal; temporal scale of same size as dorsal scales of lateral rows, but distinct from lateral body scales by its oblique orientation; ocular scale pentagonal with dorsal apex acuminate and anterior border slightly rounded at eye-level, 1.8 times higher than wide, contacting anteriorly first supralabial, anterodorsally supraocular, posterodorsally parietal and dorsally second supralabial; eye distinct, located at level of maximum width of ocular, with lower eye margin at nostril level, positioned anteriorly and almost contacting scale sutures; upper half of eyes visible in dorsal view; supraocular scale oriented obliquely, about twice as long as wide, contacting supranasal anteriorly, parietal and postfrontal posteriorly, frontal dorsally, and first supralabial inferiorly; supraocular, parietal and occipital scales visible in lateral view; middorsal head plates (frontal, postfrontal, interparietal, and interoccipital) imbricate, subhexagonal, except for subtriangular frontal, with frontal and interoccipital being slightly larger than the other two scales; middorsal head plates narrower than posterior middorsal scales; frontal contacting rostral, supranasals, supraoculars, and postfrontal; postfrontal contacting frontal, supraoculars, parietals, and interparietal; interparietal contacting postfrontal, parietals, occipitals, and interoccipital; interoccipital contacting interparietal, occipitals, nuchal and first pair of paravertebral dorsal scales; parietal slightly larger than occipital, both irregularly hexagonal and about twice as high as wide; lower margin of parietal contacting upper border of posterior supralabial and temporal, posterior margin in broad contact with occipital, dorsal margin contacting postfrontal and interparietal, anterior margin in broad contact with ocular and supraocular; lower margin of occipital contacting temporal and first scale of lateral body row, posterior margin in broad contact with first paravertebral and first scale of dorsolateral body row, dorsal margin in contact with interparietal and interoccipital, anterior margin in broad contact with parietal; four infralabials per side, subequal in size, first three higher than wide, fourth wider than high, first two pairs of infralabials almost rectangular, larger than third infralabials; mental scale single, small, lunulate; labials, chin and gular scales, and dorsal and lateral head scales with numerous scattered pores.

Dorsal scales imbricate, smooth, homogeneous, rhomboid or elliptical in shape, about 1.5 times wider than long; 267 MDS; 14-14-14 D; 258 V; 10 TS. Cloacal shield large, subtriangular in shape, about 2.2 times wider than long, bordered anteriorly and posteriorly each by five scales; 15 SC, becoming successively narrower distally, no fused scales dorsally or ventrally on tail; terminal spine conical and shorter than wide.

Color of holotype after more than 100 years of preservation in ethanol (Fig. 2, and upper left picture of Figs. 3–9)

Dorsal head scales (supranasal, frontal, supraoculars, postfrontal, parietals, interparietal, occipitals, interoccipital) except for rostral, reddish-brown with cream-colored sutures; rostral reddish-brown in posterior part and with a small cream-colored blotch on the anterodorsal part, lower (ventral) part of rostral light greyish-brown; infranasal and anterior supralabial light reddish-brown; ocular scale mostly cream-colored; posterior supralabial light reddish-brown in upper half and cream-colored in lower half; ventral head scales (mental, infralabials, scales of chin and gular region) cream-colored; each dorsal body scale with a more or less triangular, median to dark reddish-brown blotch in the center of the scale and with cream-colored lateral margins, forming a pattern of dark longitudinal stripes with cream-colored interspaces, dark stripes slightly broader than interspaces, reaching to the penultimate scale of the tail; each ventral body scale, anal plate and scales on ventral part of tail light or median brown in central part and with cream-colored margins; terminal spine cream-colored.

Osteology of holotype

Skull (Figs. 10 and 11)

Premaxilla roughly rectangular in anterior view and hexagonal in ventral view, edentulous, pierced by six foramina (two in anterior view and four in ventral view); transverse process of premaxilla absent and vomerian process single; premaxilla with internal septum composed by two laminae that support the septum nasii dorsally, expanding posteriorly to fit medially in the septomaxilla (internally); nasals paired, approximately rectangular in dorsal view, being pierced by a pair of foramina in lateral border of contact with prefrontals (foramen for the apicalis nasi); an additional pair of foramina pierce the medial contact within both nasals; a single additional foramen pierces the anterior-medial region of the nasal dorsal lamina; nasal septum descending as double medial vertical flanges that contact the premaxilla, septomaxilla and vomer ventrally (internally); prefrontals paired, subtriangular in dorsal view, in contact with septomaxilla and maxilla ventrally; septomaxillae paired, complex in shape, expanding dorsally into the naris; conchal invagination absent; ascending process of premaxilla pierced by single large foramen; internally, dorsal surface of each septomaxilla pierced by a foramen, and with a medial deep sulcus that extends from its posterior to anterior regions; vomers paired, located midventral to vomeronasal cupola, bearing transversal arms, and with short posterior arms in contact with each other posteriorly; a pair of foramina pierce the ventral lamina of the vomer; frontals paired, nearly rectangular in dorsal view, the left element bearing short anterolateral projections to attach to prefrontals; frontal pillars absent; optic nerve restricted to lateral descending surface of frontals; maxilla edentulous, irregular in shape, pierced by four large foramina in lateral view, two in the dentigerous process of maxilla; posterior process of maxilla reaching the level of the optic nerve foramen; posterior orbital element absent; parietal single, wide, representing the largest bone of braincase; parietal internal pillars (sensu Martins, 2016) absent; parabasisphenoid arrow-like, with tapered anterior tip lying dorsally to palatine, and fitting in medial line of vomeronasal cupola; in ventral view, parabasisphenoid bearing posterior-lateral projections to provide insertion for the neck muscles (Martins, Passos & Pinto, 2019); parabasisphenoid with shallow pituitary fossa and lateral sulcus; anterior opening for the palatine artery indistinct or absent in parabasisphenoid dorsal (internal) surface, internal carotid artery foramen and abduscens nerve foramen present; opening for the palatine ramus of the facial nerve formed by the lateral edge of the parabasisphenoid and the ventral edge of the parietal; basioccipital single and approximately pentagonal in ventral view, bearing lateral process to attach tendons for the neck muscles (A Martins, 2016, unpublished data); basioccipital does not participate in the formation of the foramen magnum; supraoccipitals paired, approximately rectangular in dorsal view, pierced medially (internally) by a large endolymphatic foramen; prootics paired and triangular in lateral view; prootics forming the trigeminal nerve foramen together with the parietal; prootics pierced medially (internally) by two acoustic nerve foramina, and an additional foramen ventral to the former; statolythic mass in cavum vestibuli absent; stapedial footplate apparently not co-ossified with prootic; otooccipitals paired and irregular in dorsal view, descending to contact each other ventrally to exclude the basioccipital in the formation of the foramen magnum and forming a short but distinct atlantal process (sensu Cundall & Irish, 2008); medial surface (internal) of otooccipitals pierced by an internal opening for the recessus scalae timpani and a wide foramen that forms the internal opening for the vagus nerve foramen; a reduced foramen pierces the posterior (external) surface of the otooccipital, posterior to the external opening for the vagus nerve foramen; palatines paired and triradiate; anterior margin of maxillary process flexing ventrally; palatines pierced by a foramen in its ventral surface; pterygoids slender and rod-like, not contacting quadrate posteriorly, and not extending beyond the anterior margin of basioccipital; ectopterygoid indistinct.

Suspensorium (Fig. 12)

Dentary supports a series of six teeth ankylosed to the inner surface of the anterolateral margin of dental concha; mental foramen nearly under the 6th tooth; splenial conical, visible in lateral view, representing smallest bone in lower jaw, extending from the level of the 5th tooth to contact the angular posterior; anterior mylohyoid foramen absent on splenial; posterior mylohyoid foramen on the ventral and dorsal surface of angular; angular conical, extending posteriorly to level of the posterior surangular foramen; compound bone pierced by two foramina in the surangular lamina which are approximately similar in size, anterior surangular foramen located anterior to the coronoid; foramen for the chorda tympani of the hyomandibular ramus of the facial nerve (VII) present; a small foramen pierces the retroarticular process in medial view; prearticular lamina of compound bone presenting dorsal process to support the coronoid; quadrate long and slender, about 50% of skull length, presenting a posterior process (sensu Martins, 2016); a dorsal foramen in the anterior half of quadrate absent.

Cervical vertebrae (Fig. 13)

Atlas composed by neural arches, not fused dorsally but fused ventrally to a reduced ventral element (intercentrum I sensu Holman, 2000); short lateral projections of the atlas are present; axis with short spinal process; lateral foramina of axis indistinct or absent; short lateral processes present. Odontoid process of axis osseous and sutured to axis, approximately losangular in anterior view, with an anterior tapered process; intercentra II and III ventral, compressed laterally, bearing hypapophysis pointed in lateral view (sensu Holman, 2000).

Trunk vertebrae (Fig. 13)

Trunk vertebrae at midbody dorsoventrally flattened and bearing ribs; neural arches flattened; neural spines absent; spinal processes short and distinct; neural canal in anterior view about as high as wide; epyzygapophyseal spines absent; zygosphenes present, emerging from the neural canal; zygosphenal crests laterally expanded and tapered distally; zygosphenal articular facets absent; prezygosphenal articular facets ellipsoidal; prezygapophyses expand into prezygapophyseal accessory processes, distally rounded and visible in dorsal view; zygantrum wide laterally, limited by the relatively developed zygantral articular facets; postzygapophyses laterally expanded and flattened; cotyle ellipsoidal in anterior view; supracotilar and paracotylar foramina indistinct or absent; condyle ellipsoidal; vertebrae centrum bearing lateral foramen at each side; synapophyses with no distinction between diapophyseal and parapophyseal areas; hemal keel absent; subcentral ridges absent.

Pelvic girdle (Fig. 14)

Composed by ilium, ischium, femur, and pubis. Ilium and pubis rod-like; ischium approximately rectangular, apparently fused to pubis; ilium represents the longest bone of pelvic girdle; femur approximately rectangular and curved, slightly larger than ischium, located at between the last trunk vertebrae and second cloacal vertebrae.

Variation

The paratype series consists of seven specimens, two of which are lacking the head and anterior part of body (NMW 15446:1 and NMW 15446:3). Thus information of measurements and scalation of the tail and the coloration of body and tail is based on all specimens, whereas information on other characters (e.g head measurements, skull conditions) is based only on the complete specimens.

Variation of scale counts and measurements (see Table 1 for individual data of each specimen)

250–267 MDS ($\bar{x}=260.83\pm 5.91$, n = 6); 237–258 V ($\bar{x}=247.17\pm 7.31$, n = 6); 14–19 SC ($\bar{x}=17.25\pm 1.83$, n = 8); TL of 110–211 mm ($\bar{x}=149.5\pm 36.84$, n = 6); TAL of 5.9–10.3 mm ($\bar{x}=8.48\pm 1.36$, n = 6); MB of 2–4.4 mm ($\bar{x}=3.04\pm 0.71$, n = 8); MT of 1.7–3.1 mm ($\bar{x}=2.34\pm 0.48$, n = 6); TL/TAL of 14.7–20.5 ($\bar{x}=18.13\pm 2.11$, n = 6); TL/MB of 43.5–58.1 ($\bar{x}=51.73\pm 5.59$, n = 6); TAL/MT of 3.3–4.3 ($\bar{x}=3.66\pm 0.41$, n = 8); HW of 2–2.8 mm ($\bar{x}=2.27\pm 0.30$, n = 6); HH of 0.4–0.5 mm ($\bar{x}=0.417\pm 0.04$, n = 6); HL of 2.4–3.6 mm ($\bar{x}=2.85\pm 0.41$, n = 6); ED of 1.3–2.3 mm ($\bar{x}=1.717\pm 0.37$, n = 6); RES of 0.3–0.4 ($\bar{x}=0.365\pm 0.35$, n = 6).

Variation of color pattern

Color pattern of paratypes mostly resembles that of the holotype except for the following (Figs. 3–9): no cream-colored blotch on anterodorsal part of rostral recognizable in one paratype (NMW 15446:4), cream-colored blotch on rostral indistinct in two paratypes (NMW 15446:7, NMW 15446:8), cream-colored blotch more distinct and larger than in holotype, covering more than half of rostral in dorsal view in one paratype (NMW 15446:5); ocular scale almost entirely light to median reddish-brown in all paratypes; posterior supralabial almost entirely reddish brown in one paratype (NMW 15446:4); some infralabials and some adjacent chin scales exhibit a light brown pigmentation in some paratypes; in some paratypes the cream-colored ultimate part of the tail covers also the scales adjacent to the terminal spine.

Qualitative and quantitative variation of skull and lower jaw (n = 6; holotype condition indicated with asterisk)

Dentary teeth 5 (n = 3; 50%) or 6* (n = 3; 50%); premaxilla pierced by two foramina in anterior view and two large foramina in ventral view (n = 1),three in ventral view and two in anterior view (n = 1) or two in anterior view and four in ventral view (n = 5*); medial sulcus of premaxilla present (n = 1) or absent* (n = 5); maxilla perforated by one (n = 1), three (n = 1), four* (n = 2), five (n = 1) or six (n = 1) foramina; projections for the attachment of neck muscles in parabasisphenoid absent (n = 5; Fig. 15B) or present* (n = 1; Fig. 15A, yellow arrows), projections for the attachment of neck muscles in basioccipital absent (n = 5; Fig. 15B) or present* (n = 1; Fig. 15A, red arrows); statolythic mass present (n = 3; Fig. 15C) or absent* (n = 3; Fig. 15D); basioccipital with medial recess (n = 2; Fig. 15B) or not* (n = 4; Fig. 15A, black arrow); lateral recess of nasal present (n = 1; Fig. 15E) or absent* (n = 5; Fig. 15F).

Postcranial quantitative variation

Precloacal vertebrae 231–248 ($\bar{x}=240\pm 6.5$, n = 6); caudal vertebrae 14–21 ($\bar{x}=18\pm 2.7$, n = 5). Correlation (n = 5) between middorsal scales and precloacal + cloacal + caudal vertebrae (0.99:1), between midventral scales and precloacal vertebrae (0.97:1), and between subcaudal scales and cloacal + caudal vertebrae (1:1.3). Pelvic girdle located at the level of the 229th (=penultimate) trunk vertebrae and first cloacal vertebrae (NMW 15446:2), 233–234th (=penultimate and last) trunk vertebrae (NMW 15446:4), 246th (=last) precloacal and second cloacal vertebrae (NMW 15446:5), 248th (= last) trunk and second cloacal vertebrae (NMW 15446:6), 240th (=last) trunk and first cloacal vertebrae (NMW 15446:7) and 238th (=last) trunk and second cloacal vertebrae (NMW 15446:8).

Postcranial qualitative variation (n = 6; holotype condition indicated with asterisk)

Ventral element of atlas absent or not ossified to neural arches (n = 3) or absent with neural arches fused ventrally* (n = 3); anterior hypapophysis of axis pointed* (n = 5) or rounded (n = 1); posterior hypapophysis of axis rounded (n = 1), truncated (n = 3) or pointed* (n = 2); hypapophysis of axis fused (n = 1) or not* (n = 5); femur fused (n = 1) or not* (n = 5) to ischium.

Etymology

The specific epithet is an agglutination of the Latin nomen “ignis” which means fire and the proper noun “Rio” as an acronym for the Brazilian city of Rio de Janeiro. This name was chosen in honour to the Museu Nacional do Rio de Janeiro/UFRJ, Brazil’s oldest scientific institution with the largest South American collections of zoology, anthropology, geology and paleontology. Many of the precious collections pertaining to the zoology department (mostly invertebrates), anthropology, geology and paleontology were completely destroyed in the disastrous fire in its main building on September 2nd 2018. Due to historical neglection of this institution from the Brazilian government, added with substantial funding decrease in the past 5 years the museum did not receive sufficient money to fullfil basic safety standards—such as fire protection. The description of this new species, with specimens housed in a scientific collection for more than 100 years highlights one of the several importances of zoological collections in housing relevant material to understand the diversity of life, and also reinforce that such collections are timeless treasures for science. Such collections should receive strong attention in government investments as they contribute to the global development of science.

Distribution and natural history

Epictia rioignis is currently known exclusively from its type series, from Corinto, Nicaragua (See comments under Discussion).