Sifting through material extracted from 420-million-year-old rocks along the England–Wales border, scientists have found what appear to be charcoal remnants of the earliest known wildfire.
The carbonized bits of stem are black, brittle, and shiny, and they leave streaks when rubbed against other materials. It usually takes temperatures that exceed 400°C to form such charcoal, says Dianne Edwards of Cardiff University in Wales. She and her Cardiff colleagues also found many small plant fossils that had been charred only on their outer surfaces. That feature suggests a slow, smoldering fire, Edwards notes. The researchers lay out their argument for such a scenario in the May Geology.
The discovery of a charred fossilized particle of fecal matter—probably left by a millipede—that was chock-full of plant spores hints that the ancient fire burned living vegetation as well as the fuel left on the ground from previous growing seasons. The oldest unequivocal evidence for wildfire dates to about 360 million years ago (SN: 5/19/01, p. 309: Available to subscribers at They’re not briquettes, but they’ll do), the researchers note.