A late Miocene leaf assemblage from Coromandel Peninsula, New Zealand, and its climatic implications

Abstract

A late Miocene (6–6.5 Ma; Kapitean and latest Tongaporutuan stages) fossil leaf locality is situated at Mataora in the southern Coromandel Peninsula of the North Island, New Zealand (latitude 37°S). It includes well-preserved remains of a new genus and species of conifer, Mataoraphyllum miocenicus, considered to be a phyllodinous Taxaceae. Other conifers include a new species of Phyllocladus, P. palmerii, and a small scale-leafed Podocarpaceae. There are five angiosperms, including a small-leafed Epacridaceae species, Myrsine waihiensis sp. nov., (Mysinaceae) Pseudopanax (Araliaceae), and two of unknown affinity. The relatively small leaf size, low biodiversity and taxonomic content suggest low, open vegetation under a relatively cool but wet climate; current subalpine to upper forest limit vegetation is a close analogy. The fossil assemblage indicates that mean annual temperatures may have been cooler at 37°S than today for the late Miocene.

Key words:

• New Zealand
• Miocene
• fossil leaves
• cuticle
• Taxaceae
• climate

Acknowledgements

We thank land owner Richard Palmer for kindly allowing access to the fossil locality. The Herbarium of the Botany Department, University of Otago, and the Dunedin Botanical Gardens are both thanked for supplying comparative leaf material. The comments of two anonymous reviewers are greatly appreciated.