A first for bats

摘要

Which came first as bats evolved - flight or echolocation? Newly described fossils favour the flight-first hypothesis. But these creatures may have been otherwise equipped for flying at night. A long-standing debate about the processes that led to the evolution of modern bats takes a new twist with the discovery of remarkable fossil bats recovered from the Green River formation in Wyoming. The fossils, which constitute a new genus and species, are described by Simmons et al. on page 818 of this issue. Phylogenetic analysis and comparison with other fossil bats recovered from the same formation, and from the Messel formation in Germany, indicate that this is the most ancient species of bat yet discovered.