Can modern-day plants trace their New Zealand ancestry?

January 21, 2010

One hundred million years ago the earth looked very different from how it does today. Continents were joining and breaking apart, dinosaurs were roaming the earth, and flowering plants were becoming more widespread.

The southern hemisphere supercontinent known as Gondwana formed around 180-200 mya during the breakup of Pangaea and then began to split apart about 167 mya. As scientists reconstruct the history of these land masses and life during this period, many questions arise. For example, is the current flora of New Zealand derived from that grew on Gondwana before its breakup, or derived from plants that more recently dispersed to New Zealand?

Recent research published in the January issue of the by Dr. Gregory Jordan of the University of Tasmania and a team of researchers from New Zealand and Austria explore the answer to these questions based on observations of two macrofossils from the Late Oligocene/Early Miocene time period (28-15 mya) in New Zealand.

Based on observations and evolutionary analyses, Jordan and colleagues identified the two fossils as members of the epacrid subfamily of the plant family Ericaceae, known as the heath family. Their data demonstrate that by the Early Miocene, New Zealand was home to at least two different of epacrids. Past examples of Ericaceae fossil pollen in New Zealand have suggested that the family's presence in New Zealand dates back to the Late Cretaceous period (66.5-99.6 mya), but these recent evolutionary analyses suggest a much younger history for most groups of plants in that region.

"The epacrids encapsulate many of the problems that have fascinated botanists in the ," Jordan said. "How important was Gondwana? Why do we have so many sclerophylls? How do sclerophylls work? We have only just started to work these plants out."

Cyathodophyllum novae-zelandiae is the first unambiguous, pre-Pleistocene macrofossil from the tribe Styphelieae identified, and it appears to be from a lineage of plants that is now extinct. Richeaphyllum waimumuensis was identified as a member of the tribe Richeeae, but the scientists are unsure about whether it is from an extant or extinct lineage.

Although pollen from the fossil record has demonstrated that members of the Ericaceae plant family have been present in New Zealand since the Late Cretaceous, this research demonstrates that the presence of ancient fossils from a plant family may not provide evidence regarding the history of modern members of the family, providing a cautionary note to other researchers trying to reconstruct the history of a group of plants. Discovery of new macrofossils and/or detailed examinations of fossil pollen combined with evolutionary analyses may help to answer questions of whether the ancestors of current plants coexisted with dinosaurs in New Zealand.

"Delving into the details of plant fossils can give you surprises," Jordan said. "The fossil record of pollen could be read to say that this group of plants is a relic from the breakup of Gondwana—but by combining the leaf fossils and evidence from molecular biology, it looks like exactly the opposite is true."

Explore further: DNA sequences and fossils show Proteaceae spread by continental drift and transoceanic dispersal to modern continents

More information:

Related Stories

Giant bird feces records pre-human New Zealand

January 12, 2009

( -- A treasure trove of information about pre-human New Zealand has been found in faeces from giant extinct birds, buried beneath the floor of caves and rock shelters for thousands of years.

Unexpected amber find rewrites botanical history

October 2, 2009

( -- An unexpected discovery made by Macquarie University PhD student Sargent Bray about the origin and nature of chemical compounds contained in ancient amber has changed our understanding of when modern flowering ...

Extinct moa rewrites New Zealand's history

November 18, 2009

( -- The evolutionary history of New Zealand's many extinct flightless moa has been re-written in the first comprehensive study of more than 260 sub-fossil specimens to combine all known genetic, anatomical, geological ...

Recommended for you

New gene map reveals cancer's Achilles heel

November 25, 2015

Scientists have mapped out the genes that keep our cells alive, creating a long-awaited foothold for understanding how our genome works and which genes are crucial in disease like cancer.

Insect DNA extracted, sequenced from black widow spider web

November 25, 2015

Scientists extracted DNA from spider webs to identify the web's spider architect and the prey that crossed it, according to this proof-of-concept study published November 25, 2015 in the open-access journal PLOS ONE by Charles ...

How cells in the developing ear 'practice' hearing

November 25, 2015

Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.