"The King of the Beasts" by Philip José Farmer

First appeared in Frederik Pohl's Galaxy. Reprinted by Tom Boardman, Jr., Frederik Pohl, Jane Yolen, Edmund J. Farrell, Thomas E. Gage, John Pfordresher, Raymond J. Rodrigues, Robert R. Potter, Joseph D. Olander, Martin Harry Greenberg, Isaac Asimov, Charles G. Waugh, Robert Weinberg, Stefan Dziemianowicz.

Summary:

Zoo of extinct Earth beasts reconstructed from bones, including the most dangerous...

Spoiler & Commentary:

Drum roll. "Man!" That seems to be the punchline for many of these short shorts. It must have been potent in its day: Look at all of its reprints. Isaac Asimov writes in his usual dry wit, "That's going too far."

Asimov collected this as a mad scientist tale. Farmer hid from us who the speakers were in a sort of POV cheat so that we might guess the character were human. Instead, they must be alien.

UPDATE: Due to the popularity of this post and to a comment below asking for a more explicit discussion of theme, I finally expanded the commentary on this story here.