'Zombie ant parasite' uncovered
Ants were being turned into zombies by a mind-control fungus 48 million years ago, scientists have learned.
The evidence is an ancient fossilised leaf bearing unmistakable traces of a natural horror story.
Dr David Hughes, from the University of Exeter, who studied the find, said: "This leaf shows clear signs of one well-documented form of zombie parasite, a fungus which infects ants and then manipulates their behaviour."
The parasite, Ophiocordyceps unilateralis, appears to take over the minds of infected ants.
The insects are forced to leave their nests and head for a leaf that provides ideal conditions for the fungus to reproduce.
On arrival the ants are compelled to bite hard on a major vein of the leaf before dying. The "death grip" leaves the ant in a perfect position for the fungus to grow and release its infectious spores.
The death grip bite leaves a very distinctive mark, and it was this scientists discovered on the 48-million-year-old leaf specimen from the Rhine Rift Valley in Hesse, Germany.
"The evidence we found mirrors very closely the type of leaf scars that we find today, showing that the parasite has been working in the same way for a very long time.
"This is, as far as we know, the oldest evidence of parasites manipulating the behaviour of their hosts and it shows this parasitic association with ants is relatively ancient and not a recent development."
The research is reported in the Royal Society journal Biology Letters.