The Komodo monitor lizard is covered with “chainmail” of osteoderms: bone plates in the dermis. Also, only adults have it, according to The Anatomical Record. Apparently, the researchers believe that this armor serves to protect against other Komodo dragons while facing each other over territory.
Komodo monitor lizards or Komodo dragons (Varanus komodoensis) live on the Indonesian islands of Komodo, Flores, Rincha and Gili Motang. These are the largest lizards on the planet, on average they weigh 70 kilograms and reach a length of three meters. Researchers believe that its size is due to the gigantism of the islands, since in the four islands where they live, lizards are the only predators.
Reptiles lead a solitary lifestyle, they meet with other individuals only during hunting, eating prey and mating. In the mating season, males face each other for females and territory. The females do not support the winner much and at first they resist their courtship with the help of teeth and claws.
Previously, biologists found oranoderma: ossifications, which often take the form of platelets and grow in one of the layers of the skin, the dermis, in the monitor lizard (genus Varanus). The researchers also reported the presence of osteoderma on the head of the Komodo monitor lizards, but it was not clear if all the lizards had it or only adults, and what areas they covered.
Now, researchers from the University of Texas at Austin, led by Jessica A. Maisano, performed a high-resolution computed tomography on two Komodo dragons. One individual was an adult male who died at the Fort Worth Zoo in Texas at the age of 19.5, and the second was only two days from the San Antonio Zoo. Since the 2.5-meter monitor lizard did not fit in the device, the authors performed a tomography of only his head.
Scientists have discovered that the “chainmail” of bone excrescences covers almost the entire head of an adult, with the exception of the eye sockets and nostrils. But the baby had no osteoderm at all.
The scientists explained this difference by the fact that Komodo adult monitor lizards have to defend themselves against their rivals and aggressive females. While young people spend a lot of time in trees, where they do not run the risk of encountering an aggressive relative, adult monitor lizards are too heavy to climb trees.
The authors point out that conducting experiments with only one adult is not very correct, but they did not find other dead Komodo lizards, although they reviewed 171 vertebrate collections from 12 countries. It is even more important for researchers to create collections in zoos and exchange information with colleagues from other countries.
Earlier this year, scientists collected the genome of Komodo dragons and discovered how lizards acquired a good sense of smell, allowing them to smell prey at a distance of several kilometers and protect them from anticoagulants from their own saliva.