An extremely rare cyclops shark, recently confirmed in Mexico, is an editor's pick for one of the ten oddest life-forms found in 2011.
The 22-inch-long (56-centimeter-long) fetus has a single, functioning eye at the front of its head, scientists announced in October. The eye is a hallmark of a congenital condition called cyclopia, which occurs in several animal species, including humans. (See "Cyclops Myth Spurred by 'One-Eyed' Fossils?")
Scientists have documented cyclops shark embryos a few times before, said Jim Gelsleichter, a shark biologist at the University of North Florida in Jacksonville.
The fact that none have been caught outside the womb suggests cyclops sharks don't survive long in the wild.
Ten Weirdest Life-forms of 2011: Editors' Picks
A cyclops shark, a demon bat, and an albino spider are among National Geographic News's picks for the year's weirdest life-forms found this year.