Diatomyidae as a Lazarus taxon due to this gap. The only other mammal Lazarus taxon with a comparable time gap between it and its most recently known fossil relative is the monito del monte, which is part of a marsupial family (Microbiotheriidae) also most recently known from Miocene deposits. Mary Dawson described Laonastes as the "coelacanth of rodents". The analysis of mtDNA 12S rRNA and cytochrome b sequence by Jenkins et al. allied Laonastes with African hystricognath rodents, namely the blesmols and the dassie rat. Support for such a placement was fair, but the exact position could not be resolved. Huchon et al. conducted a large-scale molecular phylogeny of rodents, including representatives of all major rodent taxonomic groups, based on 5.5 kb of sequence data from four nuclear and two mitochondrial genes, and a short, interspersed element, insertion analysis including 11 informative loci. Their molecular data place Laonastes robustly as a sister clade of Ctenodactylidae, and support an ancient divergence during the Lutetian (Early/Middle Eocene, ~44 mya). The earlier molecular study was in error due to long branch attraction and inadequate sampling. Etymology The genus name for this animal, Laonastes, means "inhabitant of stone" (from Greek λαας = laas = stone, gen: λαος = laos = of stone and Greek ναστης = nastes = inhabitant). This is in reference to its presence around limestone rocks and also to the country where it was recently discovered. The specific epithet aenigmamus means "enigma mouse" (from Greek αινιγμα = ænigma and μυς = mus, "mouse") referring to its unknown position among the rodents (Jenkins et al., 2004). Discovery The first specimens were found for sale as meat at a market in Thakhek, Khammouan, in 1996. Remains of three additional animals were obtained in 1998 from villagers and in an owl pellet. Return trips to Laos by the Wildlife Conservation Society researchers uncovered several other specimens. These new discoveries have prompted the suggestion that the animals may not be as rare as once thought. On June 13, 2006, David Redfield, a professor emeritus of Florida State University, and Thai wildlife biologist Uthai Treesucon announced they had captured, photographed, and videotaped a live specimen of the species in the village of Doy in Laos. Description The animals look generally like rats, with thick, furred tails similar to a squirrel's, but limp. The head is large, with round ears and a somewhat bulbous bridge of the