Fossils’ ear design hints at aquatic lifestyle

One of Earth’s earliest-known four-limbed creatures–long thought to have been a land dweller at least part of the time–could hear best when it was underwater, according to new studies of fossilized skulls.

Remains of Ichthyostega, a stout-limbed tetrapod that lived about 360 million years ago, were first described by scientists in the 1930s. Despite decades of analyses of many fossils, several features of the creature’s skull and ear region have remained enigmatic.