Earless monitor lizard
(Lanthanotus borneensis)

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.

Earless monitor lizards are around 20 centimetres in length, and have reduced eyes and limbs, a thick body, and strongly keeled scales. Despite the name, it is capable of hearing, although it lacks a tympanum or other visible signs of ears. It is a burrowing, nocturnal animal, feeding on earthworms and similar prey. In captivity, it has been known to eat squid, pieces of fish and liver. Like its closest relatives, it is oviparous, although little else is known about its reproduction.

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.