Oct. 18 - A researcher at the University of Manchester thinks he may have solved a riddle that has baffled scientists for years. How can a wingless insect just two millimetres long travel over water to colonise an island habitat where it now thrives ? Dr David Penney says the answer may lie inside a fossil, 16 million years old. Rob Muir has more.
Sixteen million years ago, a tiny wingless insect called a springtail hitched a ride on the back of a mayfly. But neither insect could have foreseen their fate. A blob of tree sap fell from above and hardened, entombing them in amber. The ancient insects are now visible in great detail, thanks to Doctor David Penney at the University of Manchester, who put the sample under a CT scanner for a better look at what it contained. What 3000 x-ray images taken from different angles reveal, is the first evidence of any creature using an adult mayfly for transport. The springtail appears to have secured itself to its host using its prehensile antennae. Dr penney says a slight detatchment from the mayfly indicates it may have been trying to escape as the amber was setting. Today, the mayfly and the springtail are common all over the world. But scientists have long wondered how the springtail manages to colonise isolated islands far from the mainland. A sixteen million year old blob of tree sap and a twist of fate appears to answer the question.