(PhysOrg.com) — A beautifully preserved fossil identified as being of an early relative of the Asteraceae, or aster, family nearly 50 million years old suggests the plant family, which has now colonized much of the planet, originated in South America after Gondwana separated, forming South America, Australia, Africa, Antarctica and India.
Researcher Dr. Viviana Barreda and colleagues of the Argentinian Museum of National Sciences in Buenos Aires found the perfectly preserved fossil of two flowering heads in the north-west Pategonia region, in rocks along the river Picheleufu in what is now north-western Argentina, and dated it to 47.5 million years old. At the time the region was sub-tropical, with average temperatures of around 19°C.
Fossils of the Asteraceae are rare and most often only fossilized pollen grains are found, but the Patagonian fossil features two complete flowers complete with winged seeds, petals and the stems. read more