A new species of Parainversiula (Bryozoa: Cheilostomatida) from the early Miocene of Northland, New Zealand

Abstract

In this study we describe a new species of Parainversiula from the early Miocene (Aquitanian- early Burdigalian) Waitiiti Formation, Northland, New Zealand. Parainversiula gordoni sp. nov. is characterized by its large number of central spoked pores (15–21) and marginal non-spoked are-olae (29–30). A phylogenetic analysis based on morphological characters showed that P. gordoni is the sister taxon to a clade including two Australasian extant species, Parainversiula inversa and Parainversiula fertilis. This new taxon is the first fossil representative of Parainversiula recorded in the Australasian Neogene. The occurrence of the early Miocene P. gordoni partially fills a long ghost lineage in the branch leading to the modern occurrences of Parainversiula in Australasia. These results support the hypothesis of the genus dispersing to South American seas around the late Eocene to the Oligocene–Miocene boundary (23–42Ma), when the Antarctic Circumpolar Current originated and probably contributed to its expansion.