In a study of over 400 mammal species, less than half have males that are, on average, heavier than females, undermining a long-standing assumption.

Fluorescent anatomy, which recently seemed to be a quirk in unusual animals such as platypuses and opossums, was found in most living families of mammals.

The idea that most biologically male members of a species are physically larger than the females goes back to Charles Darwin’s 1871 book The Descent of Man. While this is typically true for some ...

Whales do not lay eggs. Since they are mammals, they give birth to live young. There are only five known monotremes, or egg-laying mammals, according to the Carnegie Museum of Natural History.

Early mammals were small, strictly nocturnal, and altogether less showy–verging on downright drab, as supported by a study published March 13 in the journal Science.

Study reveals molecular mechanisms behind hibernation in mammals Date: February 20, 2024 Source: eLife Summary: Researchers have characterized changes in the structure of motor proteins, called ...

Early mammals grew much more slowly but lived substantially longer than today's small mammals, with lifespans of eight to fourteen years instead of just one or two as in modern mice, for example.

During the age of dinosaurs, early mammals probably lacked the stripes and spots of their modern relatives, having uniformly dark, drab coats.

Whales, dolphins and seals living in U.S. waters face major threats from warming ocean temperatures, rising sea levels and decreasing sea ice volumes associated with climate change, according to a ...