Gemmocolus gemmata

Gemmocolus gemmata is an extinct species of sea snail, a marine gastropod mollusc, in the family Colloniidae. Fossils of the species date to early Miocene strata of the west coast of the Auckland Region.

Description

In the original description, Powell described the species as follows:
The holotype of the species measures in length and has a diameter of. The species can be differentiated from Risellopsis varia due to the presence of more strongly and evenly developed tricarinate keels, a more concave umbilical depression on the base sculpture, and a strong callus projection found on the outer reflexed edge of the inner-lip.

Taxonomy

The species was first described by A. W. B. Powell in 1935, using the name Falsicolus gemmatus. In 1992, the species was recombined as Falsicolus gemmatus, with Maxwell naming the species as the type species of the subgenus Gemmocolus. By 2009, Gemmocolus was raised to genus level, leading to the currently accepted name of the species. The holotype was collected at an unknown date prior to 1935 from southern Maukatia Bay near Muriwai, Auckland Region, and is held in the collections of Auckland War Memorial Museum.

Distribution

This extinct marine species occurs in early Miocene strata of the Nihotupu Formation of New Zealand, on the west coast of the Waitākere Ranges of the Auckland Region, New Zealand.