Crassatina senecta is a species of bivalve, a marine mollusc in the family Crassatellidae. Fossils of the species date the Pleistocene in New Zealand between 3 and 1.63 million years ago, found in deposits which represent areas of deep water.
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.
The species was first described by A. W. B. Powell in 1931, using the name Talabrica senecta. While the accepted name in New Zealand as of 2009 was Talabrica nummaria, the World Register of Marine Species lists the accepted name as Crassatina senecta. The holotype, a left valve, was collected in January 1926 by Powell from Castlepoint on the lighthouse reef in the Wairarapa, and is held in the collections of Auckland War Memorial Museum.
The species lived in deep waters.
This extinct marine species occurs in the Pleistocene, between the Mangapanian stage and the Nukumaruan stage (between 3âÂÂ1.63 million years ago) in New Zealand, including the Castlepoint Formation at Castlepoint, the Konewa Formation at Pohangina, the Whariki Formation near Parikino in the Whanganui District.