80-Million-Year-Old Snake Fossil Reveals Ancient Serpents Lived Underground

A remarkably preserved 80-million-year-old snake fossil discovered in Brazil is providing new evidence in the long-standing scientific debate about the origins of snake evolution. The three-dimensional fossil suggests that some early snakes were adapted to subterranean life long before modern snake species emerged. The new species has been named Tametara mirim, derived from the Tupi-Guarani language meaning 'adorned' and 'small.' The fossil was found in rocks dating back approximately 80 million years to the Late Cretaceous period in the state of São Paulo, Brazil, where it coexisted with ancient birds and sauropod dinosaurs. The research, led by Tiago Simões of Princeton University, involved researchers from the University of Helsinki and the Museums Victoria Research Institute and has been published in the journal Nature. Most snake fossils are flattened imprints due to millions of years of rock pressure. Of the mere ten Mesozoic snake fossils ever discovered, only three were preserved in three dimensions, making the origin of snakes—whether aquatic, terrestrial, or subterranean—a subject of debate for over a century. Tametara mirim is a rare exception, with its skull, measuring only 20 millimeters, preserved in three dimensions and complete with its cranial cavity. The fossil also represents an articulated snake skeleton. This discovery sheds light on the adaptive capabilities of early snakes to diverse environments and provides crucial clues to understanding how snakes evolved into the diverse species seen today.