Beautifully preserved: The fossil, dated at more than 50 million years old, was discovered in Patagonia and immediately evoked memories of Van Gogh's masterpiece

At first sight, the bold strokes and colours are strikingly reminiscent of one of Vincent van Gogh's famous sunflower paintings.

And the similarity is no accident - for this early masterpiece, dating back almost 50 million years, is believed to be the ancestor of modern daisies and sunflowers.

Scientists found the beautifully preserved fossil in ancient rocks from the dry, wind-swept steppes of north-west Patagonia.

Other less obvious Asteracaea plants include chrysanthemums, lettuce and artichokes.

Most ancient Asteracaea fossils found previously have consisted of nothing more than pollen grains.

The newly discovered specimen, described today in the journal Science, shows several Asteracaea hallmarks including leaf-like structures called phyllaries.

Its most prominent feature is a dense capitulum - the large and tightly packed flower head which creates the "sun" in a sunflower. This would have provided a good target for pollinating insects.

Masterpiece: Van Gogh's Sunflowers

The rocks bearing the fossil, lying along the River Pichileufu in southern Argentina, were dated to around 47.5 million years old.

Scientists believe early Asteracaea flowers may have arisen in the southern supercontinent of Gondwana, before it broke apart to form South America, Africa, India, Australia and Antarctica.

The researchers, led by Dr Viviana Barreda from the Argentinian Museum of National Sciences in Buenos Aires, wrote: 'An ancestral stock of Asteraceae may have formed part of a geoflora widespread cross southern Gondwana before the establishment of effective dispersal barriers within this landmass.'

In an accompanying article, Austrian botanist Dr Tod Stuessy, from the University of Vienna, said the fossil provided 'clear... evidence of the sunflower family at an early stage of its diversification'.