Leaf fossil dating back to late Cretaceous period . Photo: Benjamin Blonder/PA Wire

Even Armageddon can have a silver lining, according to a new discovery about what followed the massive meteor impact that wiped out the dinosaurs.

Around 66 million years ago, a 10-kilometre wide asteroid or comet smashed into the earth off Mexico’s Yucatan peninsula, producing a crater 150 kilometres across.

Three-quarters of all plant and animal species − including the dinosaurs − became extinct after the event which triggered mega-tsunami, wildfires, global earthquakes and an ‘impact winter’ caused by dust blotting out the sun. But now research suggests the cataclysm proved a turning point for the deciduous plants that now dominate vegetation on earth.

After the impact, fast-growing deciduous species rapidly began to take over from the previously ubiquitous evergreens.

Lead scientist Benjamin Blonder, from the University of Arizona in the US, said: “If you think about a mass extinction caused by catastrophic event such as a meteorite impacting earth, you might imagine all species are equally likely to die.

“Survival of the fittest doesn’t apply − the impact is like a reset button. The alternative hypothesis, however, is that some species had properties that enabled them to survive.

“Our study provides evidence of a dramatic shift from slow-growing plants to fast-growing species.

“This tells us that the extinction was not random, and the way in which a plant acquires resources predicts how it can respond to a major disturbance.

“And potentially this also tells us why we find that modern forests are generally deciduous and not evergreen.”

Deciduous plants, which grow fast and lose their leaves at some point during the year, were better able to survive the changing conditions of an impact winter, the researchers believe.

Evergreen plants, such as holly, tend to have leaves that are costly to construct but robust and long-lasting. Leaves of deciduous plants are short-lived and more cheaply built, but easier to replace.

The discovery, reported in the online journal Public Library of Science Biology, followed a study of around 1,000 fossilised plant leaves dating back to a 2.2 million-year period spanning the impact event. All the fossils were collected from a rock formation known as Hell Creek that marks the site of an ancient flood plain in southern North Dakota.

The scientists also measured the density of the leaves’ vein networks, which gave a clue to their transpiration rate − the speed at which they drew water.