Puyseguria wanganuica is a species of bivalve, a marine mollusc in the family Neoleptonidae. Endemic to New Zealand and found in waters surrounding the coasts of the mainland up to a depth of , fossils of the species have been found to date back to the Pliocene.
In the original description, Powell described the species as follows:
The holotype of the species has an estimated height of , and a length of for a single valve.
The species was first described by A. W. B. Powell in 1931, using the spelling Puysegeria wanganuica. The current accepted name is Puyseguria wanganuica. Powell believed that the species was a fossil species, and the direct ancestor of P. cuneata. The holotype was collected in January 1931 from Castlecliff, Whanganui, and is held in the collections of Auckland War Memorial Museum.
The species is endemic to New Zealand, found in the waters surrounding the North Island, South Island and Stewart Island at a depth ranging between . Fossils of this species found in New Zealand date back to the Mangapanian stage of the Pliocene (3 million years ago), and have been found near Whanganui and Nukumaru near Waità Âtara, South Taranaki.