Notes on the Earless Monitor Lizard

Earless Monitor Lizard

This article is probably the most unintentionally funny article presented by the museum. Enjoy a good laugh!

The discovery of the Earless Monitor Lizard was considered very exciting by anatomists and zoologist because it was thought to be related closely to some extinct lizards and could be a link between snakes and lizards. The Earless lizard is not a monitor lizard and only loosely related to the lizard family.

The Earless Monito is a short-legged lizard. The ears are invisible from the outside and the chocolate brown skin is covered with nodules which run in six rows along the back. It has a habit of flattening its body when tapped on the back.

The type of specimen caught in 1878 is recorded as measuring 42 cm. The lizard caught in 1976 measured 438 mm and had a flattened width of 42 mm. This considered the maximum size the which the species grows since after 2 and quarter years in captivity there has been no increase in length.

When captured on 2 September 1976 the lizard was reported found with five eggs which were pale parchment in colour. One egg was cut open. Inside was a milky white suspension containing granular particles. There was no sign of a yolk.

A box measuring 128mm long X 84 cm wide X 45 cm deep with an overhanging ledge of 16 cm was filled with earth to a depth of 15 cm. A shallow tray for water and a board were placed inside the box. The box is situated so that rain can dampen the soil. Sunlight strikes the box at 4 pm. A 2-inch wire mesh is placed over the top to keep the cats from jumping in and out. The lizard spends all day under the board and rarely enters the water of its own accord.

The lizard prefers a location where temperature fluctuations are minimal. The lizard stays under the board where the temperature remained between 24.5 C-27.5 C

The natural food of the lizard was unknown. I offered both turtle eggs and Baltic plaice(a flatfish from the Baltic region) which the lizard refused to eat. It was offered worms, snail eggs, grubs, fruit, and leeches were also presented. Although there was no noticeable food intake, the lizard gained weight of 1 gram every day only to lose 1.5 grams every night. The downward trend to 79 grams may have been the result of several factors most notably a) drinking water followed by urination b)Absorbing water through the skin as it was being washed before weighing and the drying of the skin while being wiped off and all the soil may not have been removed and c)The lizard may have been eating ant eggs from a nest that developed under the board.

No more weighings were made for “some” weeks although worms, grubs etc were offered. Nearly six months later, at the beginning of March, some slivers of chicken liver were placed near its head. The next morning the liver was gone. On the night of 3 March, some strips of pigs liver were offered and by 4 March its weight had shot up to 88.0 grams. The lizard refused to eat any more and by March 13 the weight had dropped to 80.0 grams.

On the 20th of March, more pigs liver was offered and the weight went up to 92 grams. The lower portion of the lizard was visibly expanded with food. Another feed on 11 April it was offered pgs liver again and on 11 April the rotund lizard reached a size of 101 grams. It refused to eat any more liver and by August its weight had dropped to 82 grams.

The lizard began shedding its skin for the first time since captivity in July 1978 nearly two years later. By December the shedding was still incomplete. The long period of losing its skin is indicative of very little activity.

The lizard did try to bite me on one occasion. It did bite Harry Amat Engan on the finger while he was trying to feed it. There was little bleeding or pain nor did any swelling occur later.

If the lizard does not eat the liver offered it still stays under the board even when the liver starts to rot. The only time the lizard moved from under the board and buried itself under the leaves was when I offered it a piece of durian.

The claws of the lizard are very long, curved and sharp. One could expect an animal with long periods of inactivity to grow claws simply because of the lack of use. I can see no evolutionary advantage to this. I tried to get the lizard to climb a pole without success. However, when held upside down against a pole, the lizard scurried down the pole and tried to run away.

In conclusion, much remains to be discovered about the habits of this very rare lizard which has only been discovered in Sarawak.

From: Some notes on a captive earless monitor lizard, Lanthanotus Borneensis by K.R.S. Proud in the Sarawak Museum Journal December 1978

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