Phenomena of polycephaly

Jun 5, 2007 19:26 GMT  ·  By

Two heads think more than one. But it is better for them to be located in two distinct bodies.

When more than one head grows from one body, this is called polycephaly, an impairment that occurs during the embryonic stage of development.

These tortoises show that the two-headed monsters are not just something depicted from legend and myth, but a startling reality.

This angulate tortoise was found in Wellington, Western Cape South Africa and it has two heads that are joined by a common body. Otherwise, it seems normal and both heads feed on grass, leaves and softened rabbit pellets.

This species does not usually overgrow 22 cm (9 inches) and has a lengthened straw-colored shell with slightly raised shields of a black color in the middle and on the sides. Males grow larger than the females, and the tortoises retreat to the safety of their shell at the first disturbance.

They resist for long without drinking but drink a lot when they have the opportunity. This is only the second case of its kind encountered in South Africa in over 20 years; another similar individual was found in the early 1980s.

One of the heads controls the front pair of legs and the other the back. When the tortoise gets scared, each of the heads wants to move in its own direction and then the feet get all tangled up. The heads have not squabbled because "they're still too little".

A case of two-headed child was reported last month from Vietnam and this can occur in all cases: from turtles, lizards and snakes to mammals (like cows and cats). Two-headed individuals were also signaled in the case of a Mediterranean spur-thighed tortoise.

Experts say survival rates for two-headed animals tend to be lower in the wild but in captivity such animals can prosper and even reproduce.