Bugs pull rug from under India historians

The bugs, preserved in lumps of amber, show that India was not cut off from the rest of the world before joining the Asian continent 50 million years ago.

For long periods when India was an island there must have been a flow of small creatures travelling between it and the mainland.

Scientists discovered more than 700 arthropods – animals with jointed legs like insects and spiders – in the amber collected from the coast of north-west India's Gujarat province.

They were trapped and preserved in solidified sap chemically linked to a family of hardwood trees that now makes up 80 per cent of the forest canopy in south-east Asia.

The creatures turned out to have relatives as far apart as northern Europe, Asia, Australia and Central America.

This was a surprise, since according to geological theory India had been an isolated land mass for around 100 million years – enough time for its own unique species to evolve.

"The insects trapped in the fossil resin cast a new light on the history of the sub-continent," said Professor Jes Rust, from the University of Bonn in Germany.

India is believed to have "broken off" from the East African land mass 160 million years ago. It then "floated free" – travelling at around 20 centimetres per year – before crashing into Asia about 50 million years ago. The collision caused the Earth's crust to wrinkle up, forming the Himalayas.

Prof Rust said the similarities between the new fossils and those from elsewhere indicated a "lively exchange of species".

He and his colleagues, whose findings appear in the journal Proceedings of the National Academy of Sciences, believe long chains of volcanic islands may have allowed the bugs to mingle by "island hopping".