Giant 'mystery eyeball' discovered on South Florida beach:

Carli Segelson, spokeswoman for the agency, said the eyeball is slightly larger than a baseball and presumably belonged to some kind of marine animal.

"We're hoping to determine what kind, but at this point we just don't know," Segelson said. 

The eyeball is being preserved and will be delivered to the agency's research lab in St. Petersburg, where it's hoped an official identification can be made. 

Meanwhile, people are making all sorts of guesses. 

Perhaps the best comes from George Burgess of the Florida Museum of Natural History. Burgess has suggested that the eye may have belonged to a bigeye thresher shark. The species is found off Florida in moderately deep water, and the sharks are aptly named.

Other guesses have appeared on the FWC's Facebook page.

"I'm going for a whale eye ...," reads one comment. 

"Giant squid?" reads another. 

Then there was this more adventurous theory: "A giant squid ripped out a whale's eye."

Segelson said it might be several days before a precise identification is made.