Australdonta oheatora, Sartori, André F., Gargominy, Olivier & Fontaine, Benoît, 2013

Sartori, André F., Gargominy, Olivier & Fontaine, Benoît, 2013, Anthropogenic extinction of Pacific land snails: A case study of Rurutu, French Polynesia, with description of eight new species of endodontids (Pulmonata), Zootaxa 3640 (3), pp. 343-372 : 349-352

Australdonta oheatora sp. nov.

Figures 3 A, 4, 14A, 15A

Examined material (48 specimens). Holotype: MNHN 25193, Rr66. Paratypes: MNHN 25194, 8 shells, Rr66. Additional material: 35 shells, Rr66; 3 shells, Rr38; 1 shell, Rr68.

Diagnosis: Shell small, relatively high, with a shallow supraperipheral groove, without flammulations; palatal wall devoid of barriers; parietal wall with three to five barrier traces.

Description: Shell subdepressed, white to light fawn, without markings. Shell thin, opaque to pellucid; periostracum adherent, shiny. Apex flat to moderately raised, spire elevated; later whorls descending progressively more rapidly. Whorls weakly keeled peripherally; apical suture canaliculate, umbilical suture impressed. Transition between protoconch and teleoconch indistinct. Protoconch and initial teleoconch rounded in cross-section; developing a shallow supraperipheral groove extending approximately from the first quarter of the third whorl onwards. Protoconch sculptured by very fine, widely spaced spiral and axial lirae, forming a reticulated pattern; spiral lirae wobbly in aspect, particularly towards the shell axis, fading on the transitional zone between protoconch and teleoconch. Axial lirae progressively transitioning into more crowded and slightly coarser riblets, with interspaces two to four times their width, overlaying the primary axial sculpture of the teleoconch. Primary axial sculpture formed by broad, low ribs or undulations of the external shell surface, with interspaces approximately three times their width. Umbilicus wide, deep. Peristome ovate, slightly constricted by supraperipheral sulcus. Palatal barriers lacking. Parietal barriers usually represented by three, seldom by four or rarely by five traces, all extending for approximately one quarter of a whorl; first trace located very near the suture, slightly taller than the remainder; second trace rarely present, slightly lower than the third and fourth traces; third and fourth traces located in the central sector of the parietal lip, very similar in morphology; fifth trace, when present, just abaxial to the umbilical suture, slightly lower and more slender than the third and fourth traces. Other shell features that can be expressed numerically are shown in Table 2 .

Remarks: The higher shell, fine axial riblets, lack of palatal barriers and narrower umbilicus of A. oheatora immediately separate this species from previously described Australdonta with marked supraperipheral grooves, namely A. magnasulcata Solem, 1976 , A. magnasulcatissima Zimmermann et al., 2009 and A. sulcata Zimmermann et al., 2009 . A much deeper supraperipheral groove distinguishes A. anneae sp. nov. from A. oheatora .

Etymology: Oheatora is the ancient Polynesian name of the island of Rurutu. It is treated as a noun in apposition.

paratype 2 3.14 5.52 84 1.57 0.89 1.23 0.37 0.79 0.50 0.72 0.25 0.24 ...... continued on the next page

Figures

FIGURE 3. Holotypes of: A. Australdonta oheatora sp. nov.; B. A. anneae sp. nov.; C. A. sibleti sp. nov.; D. A. florencei sp. nov. Scale bars = 1 mm.

Tables

TABLE 2. Dimensions (in mm) and ratios of type specimens. See Figure 2 for the placement of measurements. Tildes (~) and dashes (–) indicate approximate values and data missing due to poor preservation, respectively. Abbreviations: ah, aperture height; aw, aperture width; d, shell diameter; h, shell height; nr, number of ribs on body whorl; sp, spire protrusion; u, diameter of umbilicus; wn, number of whorls.

Specimen	d	wn	nr	h	ah	aw	sp	u h/d ah/aw u/d sp/h
A. oheatora sp. nov.
holotype	2.57	3.95	30	1.43	0.79	1.05	0.35	0.65 0.56 0.75 0.25 0.25
paratype 1	2.93	4.16	36	1.50	0.90	1.13	0.30	0.84 0.51 0.79 0.29 0.20
paratype 2	2.79	4.31	38	1.53	0.88	1.02	0.36	0.76 0.55 0.86 0.27 0.23
paratype 3	2.67	3.80	35	1.33	0.74	1.07	0.25	0.62 0.50 0.69 0.23 0.19
paratype 4	2.71	3.91	32	1.37	0.75	1.05	0.31	0.70 0.51 0.72 0.26 0.23
paratype 5	2.47	3.87	28	1.33	0.77	1.07	0.27	0.50 0.54 0.72 0.20 0.20
paratype 6	2.64	3.88	30	1.37	0.78	1.03	0.34	0.53 0.52 0.75 0.20 0.25
paratype 7	2.55	3.79	35	1.30	0.70	1.01	0.31	0.67 0.51 0.69 0.26 0.24
paratype 8	2.61	3.67	33	1.18	0.86	1.02	0.16	0.59 0.45 0.84 0.23 0.13
mean	2.66	3.93	33.00	1.37	0.80	1.05	0.29	0.65 0.52 0.76 0.24 0.21
standard deviation	0.14	0.20	3.28	0.11	0.07	0.04	0.06	0.11 0.03 0.06 0.03 0.04
A. anneae sp. nov.
holotype	3.30	4.15	36	1.41	0.92	1.27	0.38	0.86 0.43 0.73 0.26 0.27
paratype 1	2.72	3.58	33	1.08	0.74	0.95	0.33	0.79 0.40 0.78 0.29 0.30
paratype 2	2.45	3.78	–	0.98	0.57	0.92	0.27	0.69 0.40 0.63 0.28 0.28
mean	2.82	3.84	34.50	1.16	0.75	1.04	0.33	0.78 0.41 0.71 0.28 0.28
standard deviation	0.43	0.29	2.12	0.22	0.18	0.19	0.06	0.08 0.01 0.08 0.02 0.01
A. sibleti sp. nov.
holotype	3.01	4.16	56	1.26	1.08	1.21	0.00	0.93 0.42 0.89 0.31 0.00
paratype 1	3.10	4.53	51	1.31	1.06	1.11	0.00	1.14 0.42 0.96 0.37 0.00 ...... continued on the next page