A new species and a new record of endobenthic Clavagellidae (Bivalvia: Anomalodesmata: Clavagelloidea) from the Oligocene and Miocene of New Zealand

The endobenthic 'watering pot shell' Clavagella maxwelli n. sp. is described from the Early Miocene, and the similarly endobenthic species Stirpulina cf. pallinupensis Morton, identified hitherto only from the Late Eocene (Priabonian) of Western Australia, is recorded from the late Early Oligocene, both from Otago, New Zealand. Previously, only Clavagella oamarutica Maxwell (Early Miocene) has been recorded from New Zealand. Although the holotypes of Clavagella maxwelli and C. oamarutica have similar tube lengths (c. 80 mm), the two species differ from each other in several important respects. C. maxwelli was a vertically (or nearly so) burrowing endobenthic species whereas C. oamarutica was a cryptic, nestling, possibly cemented species. This is the first record of Stirpulina from New Zealand. The adventitious tube of Clavagella maxwelli was secreted by the mantle from four foci, progressively enclosing the right shell valve and creating an irregular suture on its right side within the array of haphazard tubules that comprises the anterior watering pot.