This ant, preserved in amber 50 million years ago, is evidence that we may have dramatically misunderstood the environmental history of India.
Until recently, scientists believed that many of the plants and animals in the Indian subcontinent had evolved in isolation from other landmasses, during a period hundreds of thousands of years ago before India smashed into Asia. That crash created the Himalayas, and also - it was believed - brought India's unique set of plants and animals into first contact with those elsewhere in Asia and Europe. Now, however, it looks like "isolated" India actually contained a number of creatures and trees that existed elsewhere on the globe - including places like Australia and Mexico. It appears that India was once a tropical forest.
This has actually deepened the mystery of India's early biosphere, because it's unclear how the landmass acquired such diversity in isolation from other landmasses on the planet.
According to a summary of the study, in Proceedings of the National Academy of Sciences:
The array of unique plant and animal species in India are thought to have evolved during the continent's 100 million year northward journey that ended with the massive collision that formed the Himalayas. Jes Rust and colleagues extracted more than 300 pounds of amber from 50 million-year-old deposits in western India, and identified a distinctive chemical signature that suggested the resin was produced by a globally widespread family of tropical trees. The researchers dissolved the amber with solvents and extracted entire preserved specimens of more than 700 ancient insects, arachnids, and crustaceans from more than 55 families, as well as abundant plant and fungal remains. The insects revealed unexpected geographic connections to contemporary species from Asia and Australia, and to ancient ancestors found as far away as Mexico and Central America. The study offers direct fossil evidence that Indian amber contains an early record of a tropical forest with diverse fauna, and that pre-contact India may not have been as biologically isolated as suspected, according to the authors.
Read the full scientific article via PNAS