Animals

Fangy Whatcheeria measured up to 6.5 feet (2 meters) long, and more than 300 million years ago, it was the apex predator in the sinkholes-turned-lakes of the American Midwest.

An ancient worm unearthed in China has one of the oldest fossilized brains ever found. The brain's shape could also help solve a centuries-old debate about the evolution of arthropods.

A parasite that can alter animal behavior is changing the habits of infected wolves in Yellowstone, increasing aggression and goading them into taking greater risks.

The new "dwarf dinosaur" species lends more evidence to the "island rule," which posits that animals evolving on islands become smaller than their mainland counterparts.

Octopus brains may have grown smart from an enormous diversity of microRNAs that let them grow multiple types of brain cells.

Paleontologists have discovered fossils belonging to a newfound species of tyrannosaur, which could fill an important gap in the evolutionary history of T. rex.

There are two contenders for the world's largest squid, and both are giants.

Paleontologists in China have examined the remarkable gut remnants of a birdlike dinosaur that lived more than 100 million years ago.

Bites from brown recluse spiders can cause an autoimmune form of hemolytic anemia, in which red blood cells are destroyed by the immune system.

The auction house Christie's has called off the upcoming auction of a T. rex skeleton, known as Shen, after experts noticed it looked suspiciously similar to another famous T. rex specimen, Stan.

In an epic tug-of-war, it took the British angler 25 minutes to haul the monster fish, nicknamed The Carrot, to land.

Images and footage of the black-naped pheasant-pigeon were recently captured by scientists. This is the first documented sighting of the elusive bird since 1882.

Scientists recently unearthed fossils of strange ocean creatures that lived about 460 million years ago and were unlike any animal alive today.

Researchers in Spain have unearthed a never-before-seen species of ancient marine turtle, the largest of its kind ever uncovered in Europe.

Extremely detailed Cambrian fossils show that enigmatic skeleton tubes belonged to ancient ancestors of modern jellyfish.

The largest T. rex to ever live may have weighed up to 33,000 pounds.

Cows fed hemp, which is not yet an approved animal feed, behaved strangely and produced milk with THC.