REPTILIA: SQUAMATA: LANTHANOTIDAE: Lanthanotus

Lanthanotus borneensis Steindachner, 1878

Earless monitor

Photos & text by Dr. Robert G. Sprackland. Specimen at right is the holotype in Vienna, used for the illustration shown below.

Range: Confirmed only from riparian habitats in Sarawak, northwestern Borneo.

Diagnosis: An elongate, blunt-nosed lizard with small eyes, short limbs, a body covered with linear tubercles and lacking an ear opening.

Description:

Natural History: Earless monitors are known from riverine habitats, rice paddies, and caves in Sarawak. They are rarely found until local flooding drives them to the surface, or they get caught in fish traps. 

Lanthanotus is semiaquatic and capable of swimming well and staying submerged for considerable periods of time. The round tail has scales that form annuli, and is strongly prehensile. Earless monitors are excellent burrowers, and consume earthworms as part of their prey. Very little else is known about their natural biology. The late Dr. Robert Mertens kept a specimen alive in captivity for 8 years.

Reproduction: Egg layer, producing 2-4 oval eggs. Young measure about 3 1/2 inches / 7 cm at hatching.

Taxonomy & Relationships:

Variation: There is some sexual dimorphism. Males have a blunt, nearly squared lower jaw, and females have a V-shaped, narrow lower jaw.

Additional Comments:  

Type Specimen:

 Literature: