66-Million-Year-Old Wildfire Reveals the Climate During the Last Days of the Dinosaurs

Archaeologists are learning a bit more about forest fires that occurred 66 million years ago during the time of the dinosaurs. They've discovered the first fossil-record evidence of forest fire ecology in Canada, revealing a bit more about the ancient climate of our planet.

In this case, the researchers managed to discover what is essentially a snapshot of the ecology on Earth at a time when the dinosaurs were on the verge of their mass extinction. The fossil record also reveals a bit more about how forests recovered after a fire.

"Excavating plant fossils preserved in rocks deposited during the last days of the dinosaurs, we found some preserved with abundant fossilized charcoal and others without it," said Hans Larsson, one of the researchers, in a news release. "From this, we were able to reconstruct what the Cretaceous forests looked like with and without fire disturbance."

In fact, the climate was much warmer and wetter than it is today. The scientists also found that at the forest fire site, the plants were dominated by flora quite similar to the kinds that begin forest recovery after a fire today. In fact, the researchers found that these ancient forests recover after fires much like current ones; plants like alder, birch and sassafras were present in the early stages before being replaced by sequoia and ginkgo.

"We were looking at the direct result of a 66-million-year-old forest fire, preserved in stone," said Emily Bamforth, one of the researchers, in a news release. "Moreover, we now have evidence that the mean annual temperature in southern Saskatchewan was 10-12 degrees Celsius warmer than today, with almost six times as much precipitation."

In fact, the plant fossils allowed the researchers to estimate, for the first time, climate conditions for the closing period of the dinosaurs in southwestern Canada. This shows exactly what the ecology was like right before the dinosaurs went extinct.

"We won't be able to fully understand the extinction dynamics until we understand what normal ecological processes were going on in the background," said Larsson in a news release.

The findings are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.