A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought.

Squat rhinos lived in North America about 12 million years ago, congregating in huge, water-bound herds much like modern hippos.

Hubble is still going strong 35 years after it was launched into space. Celebrate its anniversary with some out-of-this-world images.

When mice encounter an unfamiliar food, neurons in a brain region called the amygdala light up (blue). If the mice start feeling sick after the meal, the same neurons get reinforced to help the mouse ...

Autism rates are higher than ever before, probably because of more expansive and sensitive diagnoses. Those numbers highlight the need for more support for people with autism.

Societal upheaval can trigger uncertainty, which makes people susceptible to cognitive traps. Experts suggest some simple tools can help.

Two cases of alpha-gal syndrome suggest that the lone star tick isn’t the only species in the United States capable of triggering an allergy to red meat.

Dubbed the “bone collector,” this caterpillar found on a Hawaiian island disguises itself while stalking spider webs for trapped insects to eat.

The first skeletal evidence of a gladiator show or execution involving an exotic animal comes from a Roman British man with bite marks from a lion.

A blob of gas seen outside the Milky Way could be a type of starless, dark matter–dominated galaxy. Some scientists are skeptical.

Rising global temperatures are driving the sharp decline in terrestrial water storage. This trend isn’t likely to change, scientists say.

A long-elusive, hypothetical subatomic particle called the axion can be simulated and potentially detected in a type of thin material.