Te Papa recently imaged its Miocene plant fossils and made the images available online. Amongst these are the tiny fossilised fruit of a coconut-like plant that grew in Aotearoa New Zealand millions of years ago. Natural history researcher Lara Shepherd discusses what we know (and don’t know) about these ‘mini-coconuts’.
Coconuts (Cocos nucifera) are a type of palm best known for producing a large fruit used as an ingredient in a range of popular dishes such as palusami, ‘ota ‘ika, laksa, piña coladas, and lamingtons. Coconuts are the only (living) species in the genus Cocos.
Coconuts are thought to have evolved in Southeast Asia. Human cultivation and selection subsequently produced larger fruits with thinner husks and a higher water content.
These were moved by Pasifika peoples across the Indian and Pacific Oceans, where they are highly valued for their many uses including as a food and water source. European voyagers later introduced coconuts to the Carribean, Brazil, and West Africa.
Coconuts in New Zealand
Coconut fruit, which float, regularly wash up on New Zealand shores and some have even germinated. However, coconuts require a tropical climate to survive to maturity so have not been able to establish.
Our fossil ‘mini-coconuts’
We may not be able to grow coconuts here but fossils of coconut-like fruit that are millions of years old have been found in several New Zealand locations.
These have three ‘eyes’ at one end, similar to coconut fruit, but are tiny – only 3 to 4cm long!
Coopers Beach in the Far North is a popular spot to find these fossils – they are eroding out of an underwater deposit offshore and occasionally wash up on the beach. However, I’ve walked along Coopers Beach at least 20 times but have only seen a single fossil coconut.
But are they coconuts?
In the 1920s these fossils were named in the same genus as coconuts (Cocos). Despite the fossils being found from Northland to Otago and spanning a timeframe of over 30 million years they are currently considered a single species – Cocos zeylandica.
The presence of these fossils has been used as evidence that Aotearoa New Zealand had a more tropical climate in the past. However, more recently it has been suggested that these fossils may instead be more closely related to another palm – the cococumbe palm (Parajubaea cocoides) from northern South America, which also has small fruit.
The fruit of cococumbe palms, as well as a number of other palm genera, also have the distinctive three ‘eyes’. Cococumbe palms, whose fruit are edible, are available to purchase in New Zealand, where they are known as the Quito mountain coconut.
Cococumbe palms grows in Colombia and Ecuador, countries much closer to the equator than New Zealand. However, they grow at an elevation of 2,000 m to 3,000 m above sea level where the temperatures are similar to Northland today.
Research is ongoing to determine how many species of ‘coconut’ we had, as well as their affinities.
Regardless of what our palm fossils actually are, there is other evidence, such as fossils of other warmth-loving plants and reef corals, suggesting Aotearoa New Zealand did have a warmer climate in the past. But it was more likely to be subtropical than tropical.
Nīkau – our southern palm
We may never have had Cocos coconuts growing in Aotearoa New Zealand but we do have our own endemic palm, the nīkau (Rhopalostylis sapida). Nīkau is the southernmost member of the palm family in the world, growing as far south as Banks Peninsula.
When Māori arrived in Aotearoa it is likely they were disappointed by the tiny fruit of nīkau. In fact, it has been suggested that the name nīkau comes from ‘niu’ (the eastern Polynesian word for coconut) and ‘kau’ which can mean empty or bare.
Thanks for sharing an interesting bit of Aotearoa’s natural history. The country you are referring to, close to the Equator is Colombia. Spelt with an o. Not Columbia. A small but important difference. Thanks for your work!
Thanks for pointing out the error Marcela – this has now been corrected.