We at Weird Animal Question of the Week got a bit heady recently looking at photos of awesome animal headgear and took the author’s prerogative to ask, “What are some different types of horns?”

Horns evolved independently in many animals to meet similar needs—first as weapons, and then as defenses against rivals, says Don Moore, director of the Oregon Zoo in Portland.

Horns likely initially inflicted body blows, but became larger and more elaborate as they absorbed blows to the head. This strategy led some animals, like pronghorns, to essentially wrestle (watch a video), whereas others, like sheep, ram their opponents.

Horns can also communicate power—big ones, for instance, may identify a herd's dominant male so that newcomers can