Now, thanks to the tomatillo find, the Solanaceae molecular clock is too young, Wilf said. During his talk, he listed 11 fossils from Laguna del Hunco, such as cycads, trees and the tomatillo, that show their molecular clocks are too young.
"Almost all of the molecular ages are younger than the fossils," Wilf said.
Wilf also reported two more striking fossils: Acorns and leaves from Castanopsis, the first oak ever found in South America, and the first evidence of the African cycad called Encephalartos from South America.
The two plants once populated a giant Gondwana forest that stretched across Australia, Antarctica, South America and Africa when the landmasses were joined in the supercontinent. Some of the ancient species still thrive in Australia and South Asian microclimates, or at Africa's southern tip, but most went extinct in South America.
Email Becky Oskin or follow her @beckyoskin. Follow us @livescience, Facebook & Google+. Original article on LiveScience.
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