Komodo dragons are self-evidently incredible creatures.
A type of monitor lizard, they are today found only on a range of Indonesian islands. They grow to be 3 meters (10 feet) long, their blood can fight against antibiotic resistance, and as soon as they smell fresh meat or a drop of blood, their slow, pondering walk turns into a vicious sprint for their next dinner – which includes deer and sometimes humans.
Their lineage never used to just exist in Indonesia, however – there’s evidence that they descended from groups of monitor lizards all over the world. Now, as revealed in the Journal of Vertebrate Paleontology, one of their ancestral cousins used to roam through Europe far more recently than anyone had thought.
Komodo dragons belong to a group of lizards known as “varanids”, with around 70-75 species found today in Africa, Australasia, and Asia. They also used to scramble along the ground in what is now France and Germany, but it was thought that at the end of the Pliocene Epoch 2.6 million years ago, when the climate became far drier and cooler, the European varanids died out.
Not so, says a team led by the Universities of Friborg and Torino.
A new fossil, found near the Grecian capital 30 years ago at a site called Tourkobounia, has finally been confirmed to be a varanid critter. Dating reveals that it lived around 800,000 years ago, which means that a mini-Komodo dragon survived through complex climate change – including some serious glaciations – right into the middle of the Pleistocene.
Known from only a fragmented collection of teeth and jaw parts, it was no larger than the length of an average adult’s forearm – relatively tiny compared to most varanids, and in particular the Komodo dragon. Based on the fact that it was living in quite low latitudes, the authors suggest that it shrank to cope with the cooling climate, and retreated to the Aegean where it was still warm enough to survive.
These weren’t the direct ancestors of the Komodo dragon, mind you – those giant beasts have been around both Asia and Australia for up to 4 million years. It either first evolved in Australia then moved to Indonesia, or first evolved in Indonesia from an ancestor.
Monitor lizards themselves, including this newly discovered European variant, have been on quite the journey. They first evolved in Asia 65 million years ago, just as the dinosaurs bit the dust. Then, via Iran, they extended into Africa 49 million years ago, and to Australia around 39 million years ago.
Land bridges between Australia and Asia formed 15 million years ago, which allowed the more gigantic varieties to eventually make it to Indonesia.