"Land mammals" refers to animals that live on land and have physical characteristics that enable them to survive and thrive on land, such as having legs for walking or running. Full definition
The analysis identifies habitat loss and hunting as the biggest reasons behind the decline of land mammals; marine species face additional threats, including pollution and accidental death in fishing nets. (sciencemag.org)
For example, scientists predicted that if whales evolved from land mammals, they should find intermediate fossils that show whales with feet. (rachelheldevans.com)
But a new study has found that the world's fastest land mammal has another, less obvious adaptation hidden away in its inner ear. (sciencemag.org)