These included the first fully aquatic mammals (whales) and flying mammals (bats), as well as rodents and primates. This sudden expansion of species diversity into new ways of life is known as ...

To answer the question of why mammals have five fingers ... five-finger plan first evolved. The first known animals to develop fingers evolved from fish around 360 million years ago and had ...

as these distinguishing rocks were first studied in Devon, England. The Devonian, part of the Paleozoic era, is otherwise known as the Age of Fishes, as it spawned a remarkable variety of fish.

This suggests the gene network that makes the elastic cartilage in the fish gills became active in reptiles’ ear canal first and then in mammals’ outer ear. “So what we imagine is ...