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Ancient Fossil Reveals Evolution Secrets of Lepidosaurs

9/20/2025

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Summary

Story summary

A 242-million-year-old fossil, Agriodontosaurus helsbypetrae, was found in Devon, UK, predating dinosaurs.
This lepidosaur is the oldest known member of its group, which includes lizards, snakes, and tuataras.
The fossil features large teeth for piercing insect exoskeletons and an open temporal bar.
Synchrotron X-ray scans revealed unexpected cranial structures, enhancing understanding of lepidosaur evolution.
The study, published in *Nature*, underscores the tuatara's significance as a 'living fossil.'

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Story summary

A 242-million-year-old fossil, Agriodontosaurus helsbypetrae, was found in Devon, UK, predating dinosaurs.
This lepidosaur is the oldest known member of its group, which includes lizards, snakes, and tuataras.
The fossil features large teeth for piercing insect exoskeletons and an open temporal bar.
Synchrotron X-ray scans revealed unexpected cranial structures, enhancing understanding of lepidosaur evolution.
The study, published in *Nature*, underscores the tuatara's significance as a 'living fossil.'