The discovery in Patagonia shows that frogs have had a tadpole stage for at least 160 million years. Here’s how the ancient frogs compare to those of today.

NASA's Perseverance rover is approaching four years of activity on the Martian surface — and all this time, the rover has ...

Plague is caused by the bacterium Yersinia pestis. The bubonic and septicemic forms — mainly infecting the lymph nodes and ...