The earless monitor lizard (Lanthanotus borneensis) is a semi-aquatic, brown lizard native to northern Borneo. It is the only species in the family Lanthanotidae, a group related to the true monitor lizards, as well as to the beaded lizards. This species is very rare, and most known specimens are preserved, though these, also, are rare. The species is primarily of interest to scientists, since it is an evolutionary outgroup for both varanid and helodermatid lizards.