callout: A single shark may run through upwards of 50,000 teeth in its lifetime. The shark pictured here is a composite. Moreover, it's a male composite. Finally, we only touch on some of the ...

"At first we had no idea what it was because sharks were not supposed to make any sounds." Scientists had always thought that ...

A small international team of marine biologists has observed the first known instance of a shark intentionally making sounds.

NPCA shares the latest archaeological discovery at Mammoth Cave National Park, which has a pretty fascinating human history, too.