Zoila didymorhyncha, Darragh, 2011

Darragh, Thomas A., 2011, A revision of the Australian fossil species of Zoila (Gastropoda: Cypraeidae), Memoirs of Museum Victoria 68, pp. 1-28 : 7-9

Zoila didymorhyncha sp. nov.

Figures 1E , 6A–E, I

Description. Shell solid, small for genus, elongate, subfusiform; base relatively flat, but rounded on either side of aperture. Spire not visible. Posterior canal long, with rounded sides, sunk into massive rounded posterior rostrum formed by extensions of inner and outer lips. Anterior canal long, with rounded sides, sunk into a thick, rather flat rostrum. Aperture somewhat sinuous; outer lip with 10–24 well-developed teeth extending along entire lip; teeth completely obsolete on one specimen. Columella lip with 3–26 well-developed teeth extending along entire lip on most specimens; teeth obsolete on one specimen. Fossula moderately developed, very shallow, bounded anteriorly by a small, weak, terminal ridge.

Dimensions.

Type locality. PL3022 cliff section at Addiscot Beach, beds Bl 09–l07, southwest of small gully, clay overlying Demons Bluff Formation , Victoria. AMG Torquay BT 6l9490. Jan Juc Formation. Early Janjukian .

Type material. Holotype P302687, collected T. A. Darragh, 4 December 1985; paratype P302685, collected T. A. Darragh 8 May 1990.

Time range. Early Janjukian, Late Oligocene.

Occurrence and material. PL3022 Addiscott Beach (three specimens) .

Remarks. The small size and the massive development of the anterior and posterior rostra separate this species from all others in the genus. In morphology, it comes closest to Zoila mulderi (Tate) , but it has a massive anterior rostrum lacking in Z. mulderi and the posterior rostrum is not notched as it is in Z. mulderi .

Etymology. Greek, didymos, double; rhynchos, snout.

Figures

Figure 1. A, Cypraeorbis medius (Deshayes,1835), × 5;B, Cypraeorbis sphaeroides (Conrad,1848),× 5; C, Cypraeorbis ventripotens (Cossmann, 1903), × 5; D, Cypraeorbis viathomsoni sp. nov. WAM 72.296, × 5; E, Zoila didymorhyncha sp. nov. P302687, × 2.6; F, Zoila campestris sp. nov. WAM 89.437, × 2.6; G, Zoila fodinata sp. nov. WAM 89.637, × 3; H, Zoila chathamensis (Cernohorsky, 1971) GNSTM 87922, × 2.3. Arrows indicate the location of the notch.

Figure 6. A–E, I, Zoila didymorhyncha; A–C, paratype, P302685, PL3022, × 1; D–E, I, holotype, P302687, PL 3022, × 1; F–H, Z. glomerabilis, paratype, P315526, Half Moon Bay, Torquay, × 1.

Dimensions.