Welcome Back Rat-Squirrel

Don't you hate it when you lose a species for 11 million years? Well, it's baaaaacck! The Rat-Squirrel of Laos:

It has the face of a rat and the tail of a skinny squirrel -- and scientists say this creature discovered living in central Laos is pretty special: It's a species believed to have been extinct for 11 million years.

The long-whiskered rodent made international headlines last spring when biologists declared they'd discovered a new species, nicknamed the Laotian rock rat.

It turns out the little guy isn't new after all, but a rare kind of survivor: a member of a group until now known only from fossils.

After 11 million years, how come it didn't evolve into something else?