Chameleons are popular pets. Part of the appeal of these lizards lies in their ability to fire their long sticky tongues out of their mouths to capture insects to eat. This tongue can actually be twice as long as their whole body. Because the tongue is flung like a projectile towards its target, it is called a ballistic tongue.
In 2020 an international team of paleontologists reported evidence that chameleons aren’t alone in having evolved a ballistic tongue. They found fossil evidence that a type of amphibian called an albanerpetontid that lived ninety-nine million years ago had a ballistic tongue too. Their evidence comes from fossil remains of the animal preserved in amber and discovered in the Southeast Asian country of Myanmar.
Paleontologists have found lots of other albanerpetontid fossils. This shows that although they are probably extinct today, they were once common animals. They were tiny. Their bodies were only about two inches long without the tail, and they had claws, scales, and armored skulls. The thing that makes the new fossils special is that the animal was trapped in amber. Amber comes from soft sticky tree sap. The sap can trap small animals, and then become rock-hard. In this state, it can preserve the detailed structure of an animal over geological ages of time.The fossil preserved a long rod-like entoglossal bone, just like a chameleon’s, along with some of the soft tissue of the tongue. All this was clear evidence of a ballistic tongue. Albanerpetontids can’t be the ancestors of chameleons. Albanerpetontids are amphibians and chameleons are reptiles. The two groups of animals must have evolved their ballistic tongues separately, along different evolutionary paths.