Pseudolibera aubertdelaruei, Sartori, André F., Gargominy, Olivier & Fontaine, Benoît, 2014

Sartori, André F., Gargominy, Olivier & Fontaine, Benoît, 2014, Radiation and decline of endodontid land snails in Makatea, French Polynesia, Zootaxa 3772 (1), pp. 1-68 : 48-49

Pseudolibera aubertdelaruei sp. nov.

Figures 25 D; 29; 36E.

Trochonanina obconica (Pease) [in part]—Aubert de la Rüe & Soyer 1958, p. 365, non Helix obconica Pease 1865 .

Examined material (3 specimens). Holotype: MNHN 25673, “ Pseudolibera spiralis n.sp. (undescribed by A. Solem) #3” [collected by E. Aubert de la Rüe in 1955 in Makatea; see remarks below]. Paratypes: MNHN 25674, 2 shells, one of which gold coated, same accompanying data as holotype.

Type locality. Tuamotu Islands: Makatea.

Diagnosis. Shell less than 6 mm in diameter, depressed, flammulated; apex flat, spire elevated; peripheral keel very short; teleoconch sculptured by very low axial and spiral riblets, not reduced on shell base; palatal wall devoid of barriers; 1 parietal barrier extending 1⅛ whorl, not bifurcated.

Description. Shell depressed, dome-shaped, white, with regularly spaced, amber flammulations on the apical surface, absent on the shell base. Shell wall very thin, subpellucid to pellucid; periostracum adherent, shiny. Apex flat; spire elevated; whorls descending progressively more rapidly. Apical suture adpressed; umbilical suture shallowly impressed. Whorls sharply concave above and gently concave below very short peripheral keel, transitioning into broadly convex toward the apical suture and shell base; junction of basal and columellar walls initially obtusely angled, developing a keel approximately from the fifth whorl onwards. Transition between protoconch and teleoconch indistinct. Protoconch sculptured by fine, low axial riblets, with interspaces c. 1–3 times their width, gradually transitioning into slightly broader and taller riblets, which comprise the primary axial sculpture of the teleoconch. Secondary axial sculpture of the teleoconch composed of fine lirae. Spiral sculpture developing approximately from the last quarter of the third whorl onwards, composed of riblets similar in morphology and spacing to the primary axial riblets, forming tiny nodules at intersections with the axial elements of the sculpture. Sculpture not reduced on shell base. Umbilicus rapidly expanding in diameter for approximately the first 3 whorls, remaining constant in diameter for c. 2 whorls, subsequently constricted by inward growth of the lower columellar wall and lip. Peristome subquadrate; columellar lip reflected. Palatal wall devoid of barriers. Parietal wall with 1 barrier, positioned slightly closer to the apical than the umbilical suture, descending gradually anteriorly and posteriorly, extending for c. 1⅛ whorl. Other shell features that can be expressed numerically are shown in Table 3.

Remarks. P. aubertdelaruei is one of three undescribed species Solem recognized among the material Aubert de la Rüe & Soyer (1958) had erroneously reported as Trochonanina obconica (see remarks under P. solemi for details). Our efforts to locate additional specimens have failed and the species is thus established based solely on the three specimens collected by Aubert de la Rüe in Makatea, without more precise geographic data. We chose the largest specimen as holotype and the shell coated in gold, presumably by Solem, as paratype 1. The much reduced axial sculpture of P. aubertdelaruei , which is too feeble to count ( Table 3), immediately sets it apart from other species of Pseudolibera .

Etymology. This species is dedicated to Edgar Aubert de la Rüe, who collected the only known specimens.

Figures

FIGURE 25. Holotypes of: A. Pseudolibera solemi sp. nov.; B. P. matthieui sp. nov.; C. P. cookei sp. nov.; D. P. aubertdelaruei sp. nov. Scale bars = 5 mm.