Neilo annectens

Neilo annectens is a species of bivalve, a marine mollusc in the family Malletiidae. Endemic to New Zealand, the species is found in deep waters of the Cook Strait, and off the eastern coast of the South Island. Fossils of the species date back to the early Pliocene.

Description

In the original description, Powell described the species as follows:
The holotype of the species has a height of, a length of, and a thickness of for a single valve, and grow to a height of with a length of. Shells of the species are more solid than N. australis, and lack the raised riblets found on the sculpture.

Taxonomy

The species was first described by A. W. B. Powell in 1931. The holotype was collected in January 1931 from near the mouth of the Waihi Stream, Hāwera, South Taranaki, and is held in the collections of Auckland [War Memorial Museum].
Taxonomist Bruce Marshall in 1978 considered N. annectens, N. sublaevis and N. rugata to be different chronological stages of the same evolutionary lineage. In 1995, N. rugata was synonymised with N. annectens by Hamish Spencer and Richard C. Willan.

Distribution and habitat

The species is endemic to New Zealand, found in the Cook Strait and eastern South Island between depths of, in areas such as the Taiaroa Canyon and Saunders Canyon. Fossils of the species are known to occur as far back as the Waipipian stage of the early Pliocene in New Zealand, and are found in the late Pliocene Tangahoe Formation. Fossil deposits may indicate that the species lived at shallower depths in the past.