The fossil had been in the known place for a few decades Smithsonian’s National Museum of Natural History in Washington, but only now did scientists see that the 270-million-year-old specimen comes from a previously unknown amphibian ancestor. They seriously named him after Kermit the Frog.
Welcome Kermitops, as the new species is officially called, does not look much like the popular Muppet. The scientists admit that it is a way to get some attention for their find. “In this way we can build a bridge between the work of paleontologists in museums and the general public,” says researcher Calvin So of the George Washington University. “Because this animal is a distant relative of modern-day amphibians and Kermit is an iconic amphibian, it was the perfect name.”
A forgotten fossil
But back to the fossil. It is a skull about 3 centimeters long with large oval-shaped holes where the eyes used to be. It was excavated in 1984 from the Clear Fork formation in northern Texas. All kinds of fossils of reptiles, amphibians and the ancestors of modern mammals have been found in the hundreds of millions of years old rock formations. In fact, there were so many that researchers at the time saw no way to study them all, so Kermit escaped them. The proto-amphibian’s skull lay waiting for decades for a researcher to take a good look.
A mixture
It was Arjan Mann who once again went through the treasure trove of Texas fossils in 2021 when his eye fell on one specimen that was only labeled ‘early amphibian’. “One fossil immediately struck me, this extremely well-preserved and prepared skull,” says Mann, who also co-wrote the study. His find turned out to be even more interesting than expected.
The skull had a mix of features that differed from those of skulls of older tetrapods, the ancestors of amphibians and other quadrupeds. For example, the portion of the skull behind the animal’s eyes was much shorter than its elongated, curved snout. This trait helped the animal, which probably resembled a fat salamander, to snap up small insects.
Unique properties
Kermit is classified among the temnospondyls, a very diverse group of primitive amphibians that survived for 200 million years until the Triassic. But because the fossil’s skull has such unique features, the researchers conclude that it must be an entirely new species, the Kermitops. The large eyes are vaguely reminiscent of the cartoon character and the addition -ops is Greek for face.
But the found skull is more than just a funny Kermit lookalike. The fossil record of early amphibians and their ancestors remains fragmentary, making it difficult to understand where frogs, salamanders and their relatives originated. An early relative, such as Kermitops, can help to better visualize the first branches of the amphibian family tree.
An inspiration
“Kermitops offers us starting points to bridge this gap and discover how frogs and salamanders developed their special properties,” So explains. The find may also inspire other paleontologists to take another look at their fossil collection. Who knows, there may be even more new species. “Paleontology is more than just dinosaurs and there are a lot of great evolutionary stories and mysteries waiting to be answered. We just have to keep looking,” Mann concludes.