Cycads not living fossils

21 October 2011 - 10:51 By Sapa-dpa
Cycads. File picture
Cycads. File picture
Image: Reggaeman

In a garden centre near you are palm-like plants called cycads that we have been told were around when dinosaurs roamed the earth 200 million years ago.

It turns out they were not, Australian botanist Nathalie Nagalingum said Friday.

"Every cycad species is under 10 million years old - and some are considerably younger," she said of research published Thursday in Science magazine.

The discovery will require the revision of textbooks that refer to cycads as living fossils, and the removal of signage in botanical gardens that trumpet them as dinosaur fodder.

Nagalingum, a researcher at Sydney's Royal Botanical Gardens, studied the characteristics of different cycads from around the world at a molecular level, and assessed how much they varied.

From the breadth of the diversity, the team calculated that the cycads around today all stem from a diversification that started only 10 million years ago, 55 million years after the last dinosaur died.

"There were cycads in dinosaur times but they were all made extinct and what we have today is a whole new suite of cycad species."

"It does mean we have to change a lot of things," she said.