Can modern-day plants trace their New Zealand ancestry?

Jan 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: Biologists help solve fungi mysteries

More information: http://www.amjbot.org/cgi/content/full/97/1/59

Provided by American Journal of Botany

5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Extinct moa rewrites New Zealand's history

Nov 18, 2009

(PhysOrg.com) -- 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, ...

Giant bird feces records pre-human New Zealand

Jan 12, 2009

(PhysOrg.com) -- 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

Oct 02, 2009

(PhysOrg.com) -- 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 ...

Recommended for you

Biologists help solve fungi mysteries

just added

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

More vets turn to prosthetics to help legless pets

3 hours ago

A 9-month-old boxer pup named Duncan barreled down a beach in Oregon, running full tilt on soft sand into YouTube history and showing more than 4 million viewers that he can revel in a good romp despite lacking ...

Chimpanzees prefer firm, stable beds

12 hours ago

Chimpanzees may select a certain type of wood, Ugandan Ironwood, over other options for its firm, stable, and resilient properties to make their bed, according to a study published April 16, 2014 in the open-access ...

User comments : 0

More news stories

Revealing camouflaged bacteria

A research team at the Biozentrum of the University of Basel has discovered an protein family that plays a central role in the fight against the bacterial pathogen Salmonella within the cells. The so cal ...

Sony's PlayStation 4 sales top seven million

Sony says it has sold seven million PlayStation 4 worldwide since its launch last year and admitted it can't make them fast enough, in a welcome change of fortune for the Japanese consumer electronics giant.