Diatomyidae

Diatomyidae is a family of rodents related to the gundis, known almost entirely from fossils until a single living species, the Laotian rock rat, was discovered in Laos. Fossil diatomyids have turned up in Pakistan, India, Thailand, China, Japan and Serbia, but the family had been presumed extinct for about 11 million years before the living species was found, making it a Lazarus taxon. Its teeth show a rare combination of hystricomorphous and sciurognathous features, including multiserial enamel on the incisors and an enlarged single premolar in both jaws.