Spinizonocolpites prominatus (McIntyre) Stover & Evans: fossil Nypa pollen, taxonomy, morphology, global distribution, and paleoenvironmental significance

ABSTRACT

The fossil species Monosulcites prominatus was described from Early Eocene sediments in Canterbury, New Zealand. It resembles the pollen of the mangrove palm Nypa fruticans. Subsequently, the new genus Spinizonocolpites was proposed with a type species, S. echinatus, which we consider to be a junior synonym of S. prominatus. However, S. prominatus has not always been recognised as the type species, with many authors deferring to the ‘original’ type, S. echinatus. Some 37 species of Spinizonocolpites have been described, though several are undoubtedly synonyms. Many have an affinity to Nypa and the earliest appeared in the Late Cretaceous, especially in northern South America, Africa, India and Borneo. The Indian subcontinent appears to have been the global centre of diversity of Nypa-like species during the Paleocene with a high diversity of Spinizonocolpites species. Nypa was most widespread globally during the Eocene, but the onset of global cooling in the late Middle Eocene resulted in the ultimate range contraction to Northern Australia, the Indonesian Archipelago, the Philippine Islands and China present day. The presence of Nypa pollen in sediment samples indicates a mangrove environment of muddy, slow moving tidal estuaries or rivers influenced by fresh and brackish waters.

KEYWORDS:

• Holotype
• fossil
• palm
• global distribution
• mangrove
• paleoenvironment
• palynology

Acknowledgments

The subject of Nypa-like pollen in the fossil record has fascinated us from the time it was first reported in New Zealand sediments by our great friend, the late David McIntyre. We have benefited from numerous discussions held over the years with colleagues from many different organisations throughout the world, and most recently CDC thanks Ian Raine for helpful discussion and for providing some additional references. The authors thank Guy Holdgate and Ian Sluiter, for providing the Regatta Point samples to CDC, and for their kind permission to include photographs of some of their specimens. We thank Susan Jarzen for her thorough review of the final version of the manuscript and Carlos Jaramillo and an anonymous reviewer for their constructive input. Finally, we thank James Crampton and his associate editors, Richard Jongens and Alan Cooper, for the opportunity to publish in the Roger Cooper Special Issue to memorialise a former colleague of two of us (DTP and CDC).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article. Fossil specimens are housed at GNS Science, 1 Fairway Drive, Avalon 5010, New Zealand.

Disclosure statement

No potential conflict of interest was reported by the author(s).