Readers with good memories for rat-related rumor might remember the news from 2005 that a carcass discovered in a Laotian meat market had been identified as a member of a previously-unknown species of rodents, Laonastes aenigmamus. An article in this week's Science (reported here) now shows how the Laotian rock rat (or kha-nyou, as it is known in Laos) is the modern descendant of an ancient species belonging to the Diatomyidae family -- which everyone had thought had gone extinct 11 million years ago. The Diatomyidae had never gone anywhere, though. It was just that, in an example of the "Lazarus effect," scientists hadn't happened to find any Diatomyid fossils from any period between then and now. Current thinking places the Diatomyidae family in the suborder Hystricomorpha. Works on the Laotian rock rat should thus be classed at 599.359 Rodentia other than Castoridae, Muridae, Sciuridae ("Class here Hystricomorpha").