BUENOS AIRES: The oldest known tadpole, the larval stage of a giant frog species that coexisted with dinosaurs approximately 161 million years ago during the Jurassic Period, has been found by scientists in Argentina to have exceptionally preserved fossil remnants.
The 16-centimeter-long fossil, according to the researchers, provides insight into the evolution of frogs and toads by demonstrating how little tadpoles have altered from their Jurassic ancestors. Although no older tadpole fossils have been discovered, the oldest known frog fossils are significantly older.
The researchers claim that the specimen, which is from a previously identified species named Notobatrachus degiustoi, is so well preserved that it has remnants of various soft tissues that are often absent from fossils. For example, the fossil preserves the tadpole’s eyes and nerves as black impressions in their anatomical positions.
The fossil was discovered in 2020 while searching for dinosaur bones on a ranch in the province of Santa Cruz, which is located in Argentina’s huge southern Patagonian region, around 2,300 kilometers south of Buenos Aires.
The majority of the tadpole’s body, including its head, is still intact. Aquatic tadpole larvae transform into adult frogs during their two-stage life cycle. This tadpole was nearing the end of its transformation.
