Studies in New Zealand Late Paleogene–Early Neogene Radiolaria

Abstract

Radiolaria from Late Eocene to Early Miocene localities in New Zealand are detailed in a series of studies in an attempt to broaden our knowledge of New Zealand Late Paleogene-Early Neogene Radiolaria, and a new technique for investigating Radiolaria is described. Chapter One introduces the studies and the rationale behind each, details the history of radiolarian work in New Zealand, and provides discussion of several points that surfaced during the studies. The points discussed are: radiolarian literature; plate production; scanning electron micrographs versus transmitted light photomicrographs; skeletal terminology; systematic paleontology and the description of new species; radiolarian classification; usefulness of strewn slides. Each study constitutes a published in press, or in review paper and is presented as a chapter. As each chapter is able to stand alone, their abstracts are given below. The reference lists for each paper/chapter have been amalgamated into a master list at the end of the thesis and so do not appear at the end of each chapter: Chapter Two - Seven New Radiolarian Species from the Oligocene of New Zealand Abstract: Seven new radiolarian species from the Oligocene Mahurangi limestone of Northland, New Zealand, are formally described. They are: Dorcadospyris mahurangi (Trissocyclidae), Dictyoprora gibsoni, Siphocampe missilis, Spirocyrtis proboscis (Artostrobiidae), Anthocyrtidium odontatum, Lamprocyclas matakohe (Pterocorythidae), Phormocyrtis vasculum (Theoperidae). Chapter Three – New Radiolaria from the Oligocene and Early Miocene of Northland, New Zealand Abstract: Thirteen new radiolarian species, two new genera and one new combination from the Oligocene and early Miocene of Northland, New Zealand, are formally described - The species are – Heliodiscus tunicatus (Phacodiscidae), Rhopalastrum tritelum (spongodiscidae), Lithomelissa gelasinus, L. maureenae, Lophophaena tekopua (Plagiacanthidae), Valkyria pukapuka (Sethoconidae), Cyrtocapsa osculum, Lophocyrtis (Paralampterium)? inaequalis, Lychnocanium neptunei, Stichocorys negripontensis, Theocorys bianulus, T. perforalvus, T. puriri (Theoperidae); the genera are – Plannapus (Artostrobiidae) and Valkyria (Sethoconidae); the combination is Plannapus microcephalus (Artostrobiidae). Standardised terminology is proposed for internal skeletal elements and external appendages. Emendations are proposed for the family Artostrobiidae and the genera Heliodiscus, Lithomelissa and Cyrtocapsa. Heliodiscus, Cyrtocapsa and Lychnocanium are established as senior synonyms of Astrophacus, Cyrtocapsella and Lychnocanoma respectively. Chapter Four – Early Miocene Radiolaria from Te Kopua Point, Kaipara Harbour, New Zealand Abstract: Radiolaria from the Early Miocene Puriri Formation at Te Kopua Point in the Kaipara area, Northland, New Zealand are documented. Six new species are described - Spongotrochus antoniae (Spongodiscidae), Botryostrobus hollisi, Siphocampe grantmackiei, (Artostrobiidae), Carpocanium rubyae (Carpocaniidae), Anthocyrtidium marieae (Pterocorythidae) and Phormocyrtis alexandrae (Theoperidae). Carpocanium is established as the senior synonym of Carpocanistrum. Chapter Five – Radiolaria from the Oamaru Diatomite, South Island, New Zealand Abstract: Radiolaria from the world-famous Oamaru Diatomite are documented with 24 new species described and three new genera erected The new species are Tricorporisphaera bibula, Zealithapium oamaru (Actionommidae), Plectodiscus runanganus (Porodiscidae), Plannapus hornibrooki, P. mauricei, Spirocyrtis greeni (Artostrobiidae), Botryocella pauciperforata (Cannobotryidae), Carpocanopsis ballisticum (Carpocaniidae), Verutotholus doigi, V. edwardsi, V. mackayi (Neosciadiocapsidae), Lithomelissa lautouri, Velicucullus fragilis (Plagoniidae), Lamprocyclas particollis (Pterocorythidae), Artophormis fluminafauces, Eucyrtidium ventriosum, Eurystomoskevos cauleti, Lophocyrtis (L.) haywardi, Lychnocanium alma, L. waiareka, L. waitaki, Pterosyringium hamata, Sethochytris cavipodis and Thyrsocyrtis (T.?) pingusicoides (Theoperidae). The new genera are Tricorporisphaera, Zealithapium (Actinommidae), and Verutotholus (Neosciadiocapsidae). Emendations are proposed to the family Neosciadiocapsidae and the genus Eurystomoskevos, and Pterosyringium is raised from subgeneric to generic level. Radiolarian faunal composition confirms a Late Eocene age for the Oamaru Diatomite. Chapter Six – Confocal Laser Scanning Microscopy: A New Technique for Investigating and Illustrating Fossil Radiolaria Abstract: Confocal laser scanning microscopy (CLSM), a technique newly applied to the study of fossil Radiolaria, offers the radiolarist clear views of single optical planes of specimens, unhindered by many of the optical effects of conventional light microscopy, while obviating the need to section or break specimens. Resulting images are of a clarity unsurpassed by conventional light microscopy and, as they are saved on computer, are easily viewed, manipulated, enhanced, measured and converted to hard copy. Used in conjunction with common radiolarian study methods CLSM is a powerful tool for gaining additional information with relatively little extra effort. Chapter Seven conveniently summarises taxonomic, stratigraphic and geographic data of all new taxa described, incorporating information gained from the studies and relevant literature. Appendices present the following: data pertaining to all illustrated specimens in this thesis from the University of Auckland Catalogue of Type and Figured Specimens; distribution of Radiolaria at Te Kopua Point; distribution of species and a species list for the Mahurangi Limestone.