Sharks are both cunning and ruthless, with uncommon guile and intelligence that exceeds some mammals and even most other fish. And while professional athletes may not have gills, these players can be compared to these vicious predators because they will do almost anything to win.
Modern sharks began to appear about 100 million years ago, but we won't go quite that far back with this slideshow. Instead, we'll focus on current athletes who have demonstrated behavior that is consistent with shark-like tendencies.
Sharks belong to the super-order Selachimorpha in the subclass Elasmobranchii in the class Chondrichthyes (according to Wikipedia here). But these "sharks" belong to the NBA, NFL, MLB and other professional sports bodies.
Meanwhile, though there are approximately 400 described species of sharks in existence, we will focus on just 20 with this article. But, like their fishy counterparts, these "sharks" are both impressive and feared by others.
The Discovery Channel's "Shark Week" hasn't yet started, but you don't have to wait. All you have to do is to check out the following.