New bryozoan species from the Pleistocene of the Wanganui Basin, North Island, New Zealand

Emanuela Di Martino,Lee Hsiang Liow,Dennis P Gordon,Paul D Taylor

doi:10.5852/ejt.2017.345

Abstract

Three new fossil bryozoan species, a ctenostome and two cheilostomes, are described and figured from Pleistocene strata of the Wanganui Basin, New Zealand. Buskia waiinuensis sp. nov., a soft-body ctenostome preserved as a mould bioimmuration, is the first fossil record of the genus from New Zealand. Microporella rusti sp. nov., which is notable for the lack of ooecia in the large suite of colonies available, is one of the most common bryozoans in the Nukumaru Limestone and Nukumaru Brown Sand shellbeds, forming large encrusting sheet-like colonies, but is uncommon in younger beds. Rare, small-sized colonies of Parkermavella columnaris sp. nov. were found as fossil in two Quaternary beds, the Nukumaru Limestone and the Upper Kai-Iwi Shellbed, and also alive on rocks from the greater Cook Strait area.

Highlights

The Wanganui Basin, located in southwestern North Island, New Zealand, contains one of the most complete late Neogene marine stratigraphic records in the world (Carter & Naish 1998)
Holotypes of the fossils are deposited in the collection of the Institute of Geological and Nuclear Sciences (GNS), Lower Hutt, New Zealand and other specimens in the palaeontological collection of the Natural History Museum, London (NHMUK), while Recent material is housed at NIWA
The Plio-Pleistocene of the Wanganui Basin contains rich bryozoan faunas that are currently being studied as exemplars of the macroevolutionary dynamics of ecological interactions through geological time (Liow et al 2016, 2017)

Summary

Introduction

The Wanganui Basin, located in southwestern North Island, New Zealand, contains one of the most complete late Neogene marine stratigraphic records in the world (Carter & Naish 1998). It is a fossilrich, proto-back-arc basin containing a thick sequence of Plio-Pleistocene siliciclastic sediments. The first report of bryozoans from Wanganui is found in Waters (1887), who described the bryozoan fauna of the Castlecliffian Tainui Shellbed at Shakespeare Cliff, sent to him by the collector F.W. Hutton. Brown (1952) described 32 cheilostome species from the Nukumaruan Mangamako horizon near Hunterville and Castlecliffian strata at Shakespeare Cliff and Castlecliff collected by C.A. Fleming in 1948. He revised the nomenclature of Waters’ specimens in the Hincks and Vine collections in the British Museum (Natural History) and in the Waters and Jelly collections at Manchester Museum

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Conclusion