Giant tadpole fossil is the oldest ever discovered

Scientists have made an incredible discovery in Argentina, unearthing the oldest-known fossil of a giant tadpole that lived over 160 million years ago during the Jurassic Period. This fossil, found in the province of Santa Cruz, surpasses the previous ancient record holder by about 20 million years.

The fossil, belonging to a species known as Notobatrachus degiustoi, was found in 2020 during a dig for dinosaur remains on a ranch in Argentina’s southern Patagonian region. Imprinted in a slab of sandstone are parts of the tadpole’s skull and backbone, along with impressions of its eyes and nerves.

Mariana Chuliver, a biologist at Maimonides University in Buenos Aires and the study author, described the fossil as the most exquisitely preserved tadpole ever found. The specimen provides valuable insights into the evolution of frogs, shedding light on how and when they evolved from tadpoles.

Researchers have long known that frogs have existed for millions of years, with evidence dating back 217 million years. However, the transition from tadpole to frog has remained a mystery. This newfound fossil, measuring about 16 centimetres in length, offers a glimpse into the early stages of a giant frog’s life.

The tadpole fossil closely resembles modern-day tadpoles, even retaining remnants of a gill scaffold system used for filtering food particles from water. This suggests that the survival strategy of tadpoles has remained consistent over millions of years, enabling them to withstand multiple mass extinctions.

Ben Kligman, a paleontologist at the Smithsonian National Museum of Natural History, not involved in the research, noted that the discovery helps narrow down the timeframe in which a frog undergoes metamorphosis. The findings of this study were published in the journal Nature, highlighting the significance of this ancient tadpole fossil.

The fossilized tadpole provides valuable information about the evolution of amphibians and their resilience throughout history. This remarkable discovery showcases the importance of paleontological research in unraveling the mysteries of prehistoric life forms and their adaptations over time.