Sunday, March 3, 2013

More on cycads and dinosaurs

Just because cycads were around with the dinosaurs it does not necessarily follow that the cycad species we see today were around with the dinosaurs. As it turns out they weren't. Research from 2011 forced a  rethink:


“All the cycad species we examined diverged from their nearest relatives in a really narrow window of geologic time, well after the dinosaurs became extinct,” said co-author Charles Marshall, director of the University of California Museum of Paleontology and a UC Berkeley professor of integrative biology. “This was a global event, and then the diversification essentially stopped in the last couple of million years. There is no other group of plants that has this remarkable pattern of diversification.”

“We can now say that living cycad species are not ancient or leftovers from dinosaur times,” said Nathalie Nagalingum, a research scientist at the Royal Botanic Gardens in Sydney, Australia, who led the study while a post-doctoral fellow in Marshall’s laboratory at Harvard University and subsequently UC Berkeley. “They evolved independently of dinosaurs only 12 million years ago. The recent radiation of cycads radically changes our view of these emblematic living fossils.”

Press reports here and the original paper in Science, Recent Synchronous Radiation of a Living Fossil, is here.

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