Episode 477 Albanerpetontidae

It’s Albert the Albanerpetontid! Further reading: Earliest example of a rapid-fire tongue found in ‘weird and wonderful’ extinct amphibians Amphibian skullllll: Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. Let’s learn about a long-extinct amphibian that looked a lot like a reptile. It’s a family of animals called Albanerpetontidae. That’s a mouthful, so instead of talking about Albanerpetontids, I’ll talk about all the various species as though they were not only a single species, but a single individual named Albert. Albert first appears in the middle Jurassic, around 165 million years ago, and disappears from the fossil record around 2 million years ago. That means it survived the extinction event that killed off the non-avian dinosaurs and many other animals, which is also true for many other amphibians. But Albert wasn’t like the amphibians we have around today. It belonged to its own order, Allocaudata. There’s a lot of confusion in general as to how amphibians are related to each other and how closely related, for instance, the frogs and the salamanders actually are. The same is true for Albert. What we do know is that Albert was definitely an amphibian, but it was also really different in many respects from modern amphibians. That’s weird, because only two million years ago Albert was still around and seems to have been fairly common. Albert fossils have been found in Europe, North America, northern Africa, and parts of Asia. Two million years isn’t all that long when you’re talking about big differences between related animal groups. But although Albert appears in the fossil record at about the same time as other amphibians, it seems to have evolved very differently in many ways. Albert looked like a salamander and was originally classified as a salamander. It was small, its body was slender and elongated, its legs were short, and it had a long tail. It had tiny teeth and seemed to prefer wet environments, which makes sense when you’re talking about an amphibian. But Albert had a lot of traits not found in other amphibians, such as scales. The scales were more fish-like than reptilian and were embedded in Albert’s skin like osteoderms, especially concentrated on the head. These scales have caused confusion for a whole lot of scientists. In 2016, for instance, scientists identified an unusual lizard found fossilized in amber as a 99-million-year-old chameleon. That’s because it had a weird bone in its jaw shaped like a little rod, which looked like a bone found in the modern chameleon’s tongue. It turns out that the lizard was no lizard at all but our friend Albert, an amphibian. The chameleon is a reptile and not related to Albert, but they share the same type of elongated tongue bone. When the skull of a second amber specimen was discovered that was even better preserved, including a tongue pad and other soft tissue, scientists were able to evaluate whether Albert used its tongue the same way that a chameleon does. One trait found in Albert skulls that scientists had long been confused about was how robust and large its skull was. Some scientists suggested that it used its big head to dig burrows, ramming its head into soft mud until it created a hole big enough to hide in. But it also had big eyes, which isn’t typical in an animal that burrows. Scientists now think that Albert’s head was so strong because it needed to withstand the forces of its own tongue. It could probably shoot its tongue out incredibly fast like a chameleon, much faster even than a frog. It’s referred to as a projectile tongue, ballistic tongue, rapid-fire tongue, or boomerang tongue. The muscles that power a chameleon’s tongue are specialized to store energy when it contracts, then launch the tongue out like someone releasing a stretched-out rubber band. Albert’s similar ability evolved separately from the chameleon’s, and much earlier. It’s also possible that Albert didn’t undergo a larval stage the way most other amphibians do. Juvenile specimens look like miniature adults, which is unusual in amphibians but ordinary in reptiles. Albert also had lizard-like claws. But we know Albert wasn’t a reptile, and in fact it may have demonstrated one of the most amphibian traits known, breathing through its skin. Many modern salamanders don’t have lungs or gills at all as adults, and instead absorb oxygen directly through the skin, called cutaneous respiration. The specialized bone in Albert’s jaw would have made it hard to breathe in the ordinary way, and we know it didn’t have gills. The big question is why Albert went extinct when other amphibians are doing just fine. We don’t have an answer for that, or not yet. While Albert did seem to be quite successful, fossils of tiny, delicate animals like two-centimeter-long amphibians are rare, and that means we don’t have the full picture of what happened two million years ago that drove...