Proc. Natl Acad. Sci. USA http://doi.org/6t6 (2015)

The Asteraceae are the most diverse family of flowering plants containing over 23,000 living species including daisies, sunflowers, lettuce and artichoke. The expansion of this family was thought to have occurred during the Eocene period as the oldest fossil Asteraceae dated from 47.5 million years ago (Ma). However, Barreda et al. have now identified fossil pollen from Antarctica that pushes back the origin of the group a further 20 million years.

Credit: FABIAN TRICARICO

The pollen was found in rocks dated to 76–66 Ma collected from the James Ross and Vega islands in Antarctica, ironically the only continent on which living Asteraceae cannot be found. It appears to have come from Tubulifloridites lilliei, a species known from previous fossil pollen samples but whose place within the angiosperm family tree had not been determined. The new samples allowed Barreda et al. to identify T. lilliei as a member of the Asteraceae and a relative of the Barnadesioideae subfamily, modern members of which are endemic to South America and primarily pollinated by hummingbirds.

This classification of T. lilliei makes it the first example of an Asteraceae that would have been a contemporary of the dinosaurs. Like them, T. lilliei was widely spread during the Cretaceous but failed to survive the mass extinction that brought that period to a close.