Oldest Tadpole Fossil Known To Science Dates Back 161 Million Years
Arthur T Knackerbracket has processed the following story:
An exquisitely preserved fossilised tadpole is the oldest ever discovered by science, dating back 161 million years, with an anatomy that is strikingly similar to some of today's species.
Palaeontologists found the fossil in January 2020 while searching for feathered dinosaursin Santa Cruz province in Argentina.
They did not achieve their goal," says Mariana Chuliver at Maimonides University in Buenos Aires, Argentina. However, after many days of digging, one team member found a stone with a particular imprint on it - a fossil tadpole."
Chuliver and her colleagues have now identified the tadpole as belonging to the extinct frog species Notobatrachus degiustoi, deciphered from the hundreds of adult specimens found in the same fossil deposit since 1957.
Until now, scientists had never unearthed tadpole fossils from before the Cretaceous Period, which began around 145 million years ago. This specimen is also the first ever fossilised tadpole from an earlier frog lineage known as stem anurans, which predates modern species, known as crown anurans.
The fossil was so well preserved that eyes and nerves are visible in its head, as well as a forelimb and part of its tail. The team estimates it would have been around 16 centimetres long, comparable to the biggest tadpoles that exist today.
[...] The tadpole's size also paints a picture of the kinds of habitat that frogs evolved in more than 160 million years ago - lots of water with few predators or competitors, she says. Something modern frog species can only dream about."
Journal reference:
NatureDOI: 10.1038/s41586-024-08055-y
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