Oldest known relative of modern lizards, snakes discovered
Researchers from the University of Bristol and University of Edinburgh have uncovered a 242-million-year-old fossil in Devon, England.
Named Agriodontosaurus helsbypetrae, it's now considered the oldest known member of the group that includes today's lizards, snakes, and tuataras.
The find is shaking up what scientists thought they knew about early reptile evolution.
Fossil shows mix of traits
Unlike modern lizards and snakes, this fossil shows a mix of traits: it had an open lower temporal bar but lacked both palate teeth and a skull hinge.
Its big, triangular teeth suggest it munched on tough insects.
These quirks hint that early lepidosaurs were trying out new skull shapes and diets soon after they first appeared.
Tuataras and their ancient relatives
The discovery puts a spotlight on the tuatara—a "living fossil" still around today.
Tuataras are all that's left from a once-diverse group with deep evolutionary roots.
Later adaptations like flexible jaws helped their relatives branch out into over 12,000 species we see now—pretty wild for something that started right after Earth's biggest extinction event.