A dolphin breaking the surface for air can seem like a reminder of its mammalian past. But evolution is not nostalgia. The same body that still needs oxygen from the atmosphere is also one of the ...

According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long ...

No, birds are not mammals. Rather, they are avians. Mammals are characterized by their milk glands, hair, vertebrae and their birthing of live young (being viviparous), according to Britannica.

Mammals are not especially diverse. Roughly 6,800 mammal species are known to exist, compared with about 8,800 species of amphibian, 11,000 species of bird and 12,500 of reptile. Yet when most people ...

Illustration showing Repenomamus robustus as it attacks Psittacosaurus lujiatunensis moments before a volcanic debris flow buries them both, ca. 125 million years ago. (Michael Skrepnick via ...

Two brand-new species of early mammals from the Jurassic period have been discovered, revealing the secrets of how we got our ears. These new species are hoped to give paleontologists insight into how ...

The platypus is one of nature’s strangest mammals. This egg-laying animal sweats milk, hunts by sensing electrical signals, carries venomous spurs, and even glows under ultraviolet light. Discover the ...

Mammals, including humans, stand out with their distinctively upright posture, a key trait that fueled their spectacular evolutionary success. Yet, the earliest known ancestors of modern mammals more ...