Recently-Discovered, Oldest-Known Tapdole Fossil Sheds Light on Tadpole Evolution

Scientists have discovered the oldest ancient tadpole fossil known to man.

Dating back over 160 million years, the new fossil—found in Argentina—is around 20 million years older than the previous record holder, AP News reported. 

The giant tadpole fossil was found in a slab of sandstone, where researchers could see parts of the creature’s skull, backbone, eyes, and nerves imprinted on the rock. Experts explained the fossil closely matches the tadpoles of today, meaning they’ve survived millions of years and several mass extinctions on their original survival skills.

“It’s not only the oldest tadpole known, but also the most exquisitely preserved,” said Mariana Chuliver, study author and biologist at Buenos Aires’ Maimonides University.

While this might seem nothing more than a cute discovery, it’s actually extremely helpful in understanding how frogs and tadpoles have evolved. 

“There are some researchers that state that probably the most [ancient] frogs didn’t have a tadpole stage,” said Chuliver. However, by discovering this new fossil, “we demonstrated that was not true.”

The fossil was of a particular frog species called Notobatrachus degiustoi, an extinct genus of frog that was around during the middle Jurassic. This genus was known for being especially large. In fact, the fossil itself was massive, and the amphibian hadn’t even fully developed from a tadpole into a frog yet.

“[This discovery] is starting to help narrow the timeframe in which a frog becomes a frog,” said Ben Kligman, a paleontologist at the Smithsonian National Museum of Natural History.