Cochlespira semiplana is an extinct species of sea snail, a marine gastropod mollusc, in the family Cochlespiridae. Fossils of the species date to late Eocene strata of the St Vincent Basin of South Australia, and the Otway Basin between South Australia and Victoria.
Description
In the original description, Powell described the species as follows:
The holotype of the species measures in height and has a diameter of . It can be distinguished from other members of the genus Cochlespira due to having a broadly conical spire. The species has a globose to sub-globose protoconch, a deviated tip which measures between 1.5-2 smooth whorls which merged with the teleoconch.
Taxonomy
The species was first described by A. W. B. Powell in 1944, using the name Coronasyrinx semiplana. In 1969, Powell recombined the species, leading to the currently accepted scientific name Cochlespira semiplana. The holotype was collected prior to 1944 from Aldinga, South Australia, and is held by the Auckland War Memorial Museum. The holotype has much of the ventral surface broken off, and represents an individual who was not fully adult.
Distribution
This extinct marine species occurs in late Eocene strata of the St Vincent Basin of South Australia, including the Blanche Point Formation, and the Otway Basin between South Australia and Victoria, at the Browns Creek Formation.
References