ANOTHER ONE BITES THE DUST:

Frogs Evolve Teeth—Again (Christine Dell'Amore, 2/10/11, National Geographic News)

Lower-jaw teeth in frogs re-evolved after an absence of 200 million years, a new study says. The discovery challenges a "cornerstone" of evolutionary thinking, according to experts. [...]

The discovery runs counter to a principle called Dollo's law, which states that physical structures lost during evolution are never regained, according to Wiens, an evolutionary biologist at Stony Brook University in New York State.