Pterostoma neehoffii (cf. Zamiaceae): a new species of extinct cycad from the middle Miocene of New Zealand and an overview of fossil New Zealand cycads

Abstract

A fossil cycad pinna fragment with dichotomising and anastomosing venation and cuticular preservation from the middle Miocene Hindon Maar deposits, Otago, New Zealand, is assigned to the extinct genus Pterostoma (Cycadales: cf. Zamiaceae) as a new species: P. neehoffii. The leaf features of the Hindon Maar fossil differ from previously reported Pterostoma-like macrofossils and dispersed cuticles from New Zealand and Australia in having the combination of narrow guard cell flanges, poorly developed epidermal cuticular ridges and apparently lacking trichomes, suggesting that there were at least three cycad species present in the Neogene of New Zealand. The fossil is also placed into a broader overview of the macrofossil and pollen record for cycads in New Zealand and their possible paleoenvironments.