Giant fossil bats out of Africa

When most of us think of Ancient Egypt, visions of pyramids and mummies fill our imaginations. For a team of palaeontologists interested in fossil mammals, the Fayum district of Egypt summons an even older and equally impressive history that extends much further back in time than the Sphinx. In the latest issue of the Journal of Vertebrate Palaeontology, these scientists report on the discovery of six new bat species dating to around 35 million years ago, which sheds new light on the early evolution of bats.

It took over 25 years of fieldwork to collect the 33 specimens that form the basis of the new study. 'That translates to a little over one specimen per year - a lot of effort for a single fossil,' said Erik Seiffert, a palaeontologist at Stony Brook University. 'But it shows just how important patience and long term field programs are to science. Our long-term commitment to field work certainly paid off in this case.' Among the new species is 'a giant among bats; though weighing in at less than a half-pound, it is one of the largest fossil bats ever discovered,' said Greg Gunnell, a paleontologist at the University of Michigan.

Fossil bats of Eocene age are rare in Africa. Only a few fragmentary remains from Egypt, Morocco, Tanzania and Tunisia were previously known. The discovery of six new kinds of bats illustrates the remarkably rich, and previously unsuspected, diversity of bats in Africa 37-34 million years ago. These discoveries provide important new information for understanding the evolution of modern bat families. It was thought that most Old World families of bats evolved and diversified in the northern hemisphere, but the new study indicates that many modern bat families only diversified and radiated after their initial dispersal into Africa. Seiffert noted that the Fayum bats include members of the most common and widespread group of living bats, 'Clearly the modern bat families have very ancient origins, and at least some of them probably originated in Africa.'

Elwyn Simons of Duke University said, 'Interestingly, it seems that primitive modern bats may have entered Africa together with primitive anthropoid primates. Only then did they diversify and disperse into the rest of the Old and New Worlds.'

Gunnell hopes that 'if we can come to understand the history of how bats came to be so intertwined within our ecosystem, then we can begin to appreciate them instead of fear them as many people seem to do.'