Scientists have traced the evolutionary origin of humans' outer ears to the gills of ancient fish through a series of gene-editing experiments.

Their skin is covered with denticles, tooth-like scales that differ from the scales of bony fish. And they have five, six, or seven gill slits per side, not one per side as in bony fish.

Their skin is covered with denticles, tooth-like scales that differ from the scales of bony fish. And they have five, six, or seven gill slits per side, not one per side as in bony fish.

A huge Mola Mola fish, also known as an ocean sunfish, found itself stranded near the Florida coast. What's a very large and ...