The Komodo dragon (Varanus komodoensis) is the largest living lizard, measuring up to 10 feet and weighing 150lbs. They are only found on the islands of Komodo, Rinca, Flores, Gili Motang, and Gili Dasmi in Indonesia.
The dragons were once thought to be from a smaller ancestor that lived on the Indonesian Islands and over time experienced the “island effect” of growing larger. The “island effect” of growing larger is thought to occur when the quality of food on an island is lower than the mainland and the animal grows larger in size to have a gastrointestinal tract large enough to process all available nutrients in the food. The giant tortoises of the Galápagos are an example of organisms that have evolved to such a large size due to “island effect”. An alternative hypothesis suggested that the dragons’ size evolved to allow them to prey on the dwarf elephants that once populated the islands. In 2009 scientists discovered fossils of giant lizards in Australia that date from 300,000 to 4 million years ago. It has been determined that the fossils are Komodo dragons. It appears the dragons evolved their large size 0n Australia and then colonized the Indonesian Islands. It is still unknown why they went extinct in Australia. Read Article
In 2009 Bryan Fry, a venom researcher at the University of Melbourne, and colleagues discovered that Komodo dragons were venomous and that the supposed deadly bite from bacteria was inaccurate. They were able to study two dragons that were euthanized at a zoo. They determined the venom decreases blood pressure, is an anticoagulant, and causes shock in its victims. When they examined the dragons’ skulls they found venom ducts between the sharp serrated teeth. The dragons don’t inject the venom into their prey through hollow fangs like rattlesnakes, instead the venom runs down the teeth and into the wound. Read Article. Read Fry’s Abstract.
Even though these giant lizards may seem like the things nightmares are made of they are suffering huge population declines. Isolated to a handful of islands the dragons have been declining for the last 2,000 years. Humans are the main cause of this decline. If more conservation efforts are not put into place these massive beasts will face extinction. Read Article.