Zoila undetermined

Zoila sp.

Figures 16C–D, M

Zoila sp. McNamara and Kendrick, 1994:34.

Description. Shell solid, small for genus, somewhat globose. Spire covered with callus, not projecting. Posterior canal short, notched. Anterior canal missing; slight trace of anterior basal extension on left flank. Aperture narrow, very slightly curved; outer lip with well-developed, elongate teeth (15 teeth preserved). Columellar lip with well-developed teeth extending along the whole aperture (18 teeth preserved). Base of shell rounded on both sides of aperture. Fossula well developed, concave, broad and spoon-shaped, bounded anteriorly by well-developed, single terminal ridge.

Dimensions.

Figured material. WAM 82.549, collected K. J. McNamara and G. W. Kendrick, September 1981.

Occurrence. Locality 12, Latitude Point, from large boulders of pink limestone fallen from upper level of cliff, Barrow Island, Western Australia. Poivre Formation, middle Miocene.

Remarks. This species is known only from a single specimen, which has a small piece of the left side of the posterior canal broken off, as well as a large portion of the right side of the anterior end, including the posterior canal. As a consequence, detailed comparison with other species is not possible; however, there is enough of the specimen preserved to indicate that it is a species of Zoila and almost certainly ancestral to the younger species occurring in Western Australia. Both aperture and fossula are very similar to those of Z. campestris sp. nov. from the late Pliocene, Roe Calcarenite. It differs from Z. campestris in that its outline is more rounded and it does not have a flat base. The dorsum is also not humped anteriorly as in Z. campestris sp. nov. It bears no close resemblance to any of the fossil species known from southeast Australia.

Zoila sp. is somewhat similar to the middle Pliocene species Zoila gendingensis (Martin, 1899) from the Upper Kalibeng Formation of Sonde, Java, Indonesia, but is not so high and does not have the flat base of that species. The dorsum is not as humped as in Zoila kendengensis Schilder, 1941 from the Pleistocene Putiangan Formation of Java and neither does it have the flat base of that species. Of the living species of the genus, it is most similar to Zoila venusta (Sowerby, 1846), known from the Great Australian Bight to Shark Bay, Western Australia.