Tiktaalik, part fish, part four-legged animal, is believed to be the first creature to develop characteristics that would help animals move out of the water and on to land. It had gills ...

Not only did they have outstandingly long teeth, but an amazing jaw that could open over 90 degrees. The thylacosmilus was ...

This deep-sea polar worm looks like it can't decide if it's dressed for a glitzy party or a gruesome massacre. The skin of dwarf crocodiles found living in a cave in Gabon is turning orange from ...

It may be this animal’s only chance to have its story told well, and forever. How about a memorable species you photographed that was endangered but seems to be bouncing back? What do you want ...

WASHINGTON — Nearly a quarter of animals living in rivers, lakes and other freshwater sources are threatened with extinction, according to new research published Wednesday. “Huge rivers like ...