This Frog Is the World’s Tiniest Vertebrate ... Kind Of

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The frogs are known to be very territorial with their dimes, which they prize above all other coinage.
Photo: E. N. Rittmeyer et al. (2012). "Ecological Guild Evolution and the Discovery of the World's Smallest Vertebrate". PLoS ONE

In a new paper, a group of American scientists claims to have discovered the smallest known vertebrate species in the world, a tiny frog measuring only 7.7 millimeters across, in the dime forests of Papua New Guinea. Hooray!

Except Theodore Pietsch of the University of Washington is all, Uh, hello? What about the male anglerfish I found a few years ago? The AP reports:

But the males of a species of deep-sea anglerfish are about 2 mm smaller, said University of Washington ichthyologist Theodore Pietsch, who described them in 2006. The males don't have stomachs and live as parasites on 1.8-inch (4.57-centimeter)-long females.

Chris Austin, who found the diminutive frog, doesn't really care. "He said he knew about the anglerfish," according to the AP, "but felt that average species size" — as opposed to looking at just one gender — "made more sense for comparison." Since there are no official rules concerning qualifications for the title of World's Tiniest Vertebrate, this is a debate that will likely never be settled, at least until someone finds a four-millimeter vertebrate about a year from now.