Missing link found in daisy chain
3 November 2010
A rare fossil of a complete flower belonging to the family Asteraceae has been found, proving for the first time that daisies existed 47.5 million years ago during the Middle Eocene era, when modern mammals and birds first emerged.
The discovery by an amateur fossil hunter in Argentina, reported in the journal Science, is unusual in showing a plant with large flower heads several centimetres across, leaf-like structures and slender stems - see image above.
Most plant fossils are of pollen grains, which fossilise more easily. Researchers identified it as a member of Asteraceae based on the grouping of the flowers and the overlapping arrangement of leaf-like structures at the base of the flower clusters. Spiny pollen grains typical of the family were also found nearby.
The ancient daisy would have lived in a tropical climate, possibly pollinated by hummingbirds, and its closest living relatives include the ornamental daisy Gerbera.
Scientists had previously speculated that the daisy family dated back about 50 million years based on genetic comparisons of living plants, but this is the first evidence to support that thesis.