Clinispira insolita, Simone, Luiz Ricardo L. & Casati, Rafael, 2013

Simone, Luiz Ricardo L. & Casati, Rafael, 2013, New land mollusk fauna from Serra da Capivara, Piauí, Brazil, with a new genus and five new species (Gastropoda: Orthalicoidea, Streptaxidae, Subulinidae), Zootaxa 3683 (2), pp. 145-158 : 147-149

Clinispira insolita new species

( Figs. 2–15)

Types. Holotype MZSP 111847. Paratypes MZSP 111828, 84 eroded shells (sta. P 4), MZSP 111829, 5 shells (sta. P 3), MZSP 111830, 5 shells (sta. P 3), MZSP 111831, 4 shells (sta. P 2), MZSP 111832, 5 shells (sta. P 1), MZSP 111833, 1 shell (sta. P 1), MZSP 111834, 2 shells (sta. P 1), MZSP 111846, 8 shells (sta. P 1) ( Figs. 8–10), MZSP 112369, 3 shells ( Figs. 11–13), MZSP 112426, 1 young shell ( Figs 14–15), USNM, 2 shells; MNRJ, 2 shells. All from type locality.

Type locality. BRAZIL. Piauí; Serra da Capivara ; Coronel José Dias municipality, close to Sítio do Mocó town, Cave Toca de Cima dos Pilão, 8 ° 51 ’47.10”S 42 ° 33 ’26.96”W (R. Casati col, 2012).

Description. Shell of about 15 mm. Color pale beige to pale brown, sometimes translucent ( Figs. 11–13). Periostracum thin, pale-brown ( Figs. 11–12). Most basal portion of adult and young specimens bulimoid ( Fig. 14). Protoconch of 2 whorls, smooth, shining ( Fig. 15), suture well-marked ( Figs. 2, 4, 5, 7, 8, 12, 14); occupying ~ 1 / 6 of shell dorsal width. Spire of ~ 5 whorls, conic, angle ~ 65 °; suture shallow but well-marked. Sculpture uniform series of axial, narrow, rather irregular undulations, from suture to suture, ~ 60 in penultimate whorl. Body whorl abruptly deviating perpendicularly from normal growth, edging outer side of preceding whorls towards apex, forming ark flanking outside entire shell; low peripheral carina from abrupt deviation up to region preceding aperture ( Figs. 3, 6, 7, 9, 11); suture of this ark similar as remaining spire suture ( Figs. 3, 9, 11). Spire axis situated ~ 30 ° in relation to arched body whorl ( Figs. 2, 5, 8, 13). Aperture placed close and slightly ventral to apex ( Figs. 2, 8, 13); peristome entirely deflected outwards, expanding ~ 30 % width of preceding whorl; aperture greatly prosocline, deviating ventrally ~ 60 ° apertural plane from transverse section; pair of wide, longitudinal, irregular furrows in dorsal and left region preceding aperture ( Figs. 4, 10, 12), corresponding to larger teeth of aperture. Aperture semi-circular, occupying ~ 1 / 5 of shell ventral surface; greatly occluded by series of narrow and tall teeth ( Figs. 2, 5, 7, 9, 11), teeth fold-like, disposed perpendicularly to peristome; as follows ( Fig. 7): 3 parietal (columellar or inner lip) teeth, located equidistant from each other on inner lip, infraparietalis (inferior) tooth ~ 8 times longer than wide, almost straight, edge broader than base, parietalis (middle) tooth similar to inferior tooth, but ~half its size, angularis (superior) tooth about as long as inferior tooth, but thinner and strongly arched (concavity inferior); single very large palatal tooth, Y-shaped tooth, corresponding to furrow of preceding dorsal region of aperture ( Figs. 4, 10, 12), with ~ 1 / 3 of body whorl’s length, middle portion taller, inferior edge thick edged, forming ark (concavity inferior) in middle level of superior half of outer lip; 3 columellaris (inferior) teeth, placed approximately equidistant in inferior half of outer lip, middle tooth largest, ~ 10 times longer than wide, edge thicker than base, smoothly arched (concavity left), left and right columellaris teeth similar to middle tooth, being ~half its size; some specimens possessing secondary, minute, similar-shaped intermediary teeth between main columellaris teeth ( Figs. 8, 9). Callus very thin, attached from third whorl to superior third part of fifty spire whorl ( Figs. 3, 9, 11). Umbilicus wanting, occluded by arched body whorl ( Figs. 3, 6, 9, 11).

Measurements (length, width and height in mm): Holotype ( Figs. 2–7): 14.6 by 9.4 by 6.2; Paratypes MZSP 111846 ( Figs. 8–10): 15.6 by 10.4 by 7.1; MZSP 112369 ( Figs. 11–13): 14.0 by 10.0 by 6.6); MZSP 112426 ( Figs. 14–15): 9.3 by 6.2.

Distribution. Only known from type locality.

Habitat. Caatinga semi-dry environment; collected inside caves.

Material examined. Types. Non-type material from type locality MZSP: 112353, 8 shells, 112360, 11 shells, 112365, 2 shells, 112375, 4 shells, 112396, 6 shells, 112404, 8 shells, 112419, 2 shells, 112428, 14 shells, 112435, 5 shells, 112440, 5 shells.

Etymology. The specific epithet is derived from the Latin insolitus, meaning unusual, uncommon, strange, and odd; an allusion to the strange shape of the body whorl.

Systematic remarks. The new genus Clinispira is clearly closely related to the South American genera Anostoma Waldehelm, 1807 , Tomigerus Spix, 1827 , and Biotocus Salgado & Leme, 1990 ; which are the genera with some degree of deviation of the body whorl and mostly well-developed teeth in a deflected peristome ( Simone, 2006). Clinispira differs from Anostoma in being smaller in size (~ 15 mm, while the Anostoma are normally over 30 mm), a more developed teeth in peristome, a base of the shell somewhat bulimuloid (while Anostoma is discoid), and mainly by a smaller degree of deviation of body whorl (~ 60 ° instead of ~ 90 °). Clinispira differs from Tomigerus and Biotocus ( Salgado & Leme, 2000) in having a narrower basal shell, in lacking some degree of dorso-ventral compression, and by a larger degree of body whorl deviation (both previous known genera have only a short displacement of aperture towards the apex). However, the peristome of Clinispira is very similar in shape and teeth components to Tomigerus-Biotocus branch, which possibly indicates a closer relationship. The strange shape of Clinispira insolita dispenses any further comparisons to other genera or species.

The young specimens of Clinispira insolita are rare, and resemble a Bulimulus Leach, 1814 species ( Fig. 14), except in having a smooth protoconch ( Fig. 15) (it is reticulate in that genus). As a noteworthy variation, some specimens appear to be more elongated ( Figs. 3, 4), while others are more circular in outline ( Figs. 9, 10, 11, 12). The shell walls in most specimens are thick and opaque. However, a few specimens have thinner and translucent shell walls ( Figs. 11–15). Whether this feature is related to youngness or a better preservation is not clear.