Thanks to ancient charcoal deposits from Wales and Poland, scientists have been able to track down the oldest wildfires. What life was like on Earth during the Silurian period is given by them.

Plants wouldn't have appeared in regions that were dry for a long time if it weren't for water. The study states that the wildfires would have burned through very short vegetation and occasionally knee- or waist- high plants.

The researchers say that the landscape would have been dominated by Prototaxites. It is thought that the fungus was able to grow as high as nine meters.

One of the samples used in the study. (Glasspool et al., Geology, 2022)

Ian Glasspool is a paleobotanist from Colby College in Maine.

As soon as there is fuel, at least in the form of plant macrofossils, there is fire.

In order for a wildfire to exist, it needs fuel, an ignition source, and enough oxygen.

The researchers think that Earth's atmospheric oxygen levels were at least 16 percent.

During the course of Earth's history, that level has varied greatly. The team thinks the atmospheric oxygen levels may have been as high as 21 percent.

It's very useful for paleontologists. Knowing the details of the oxygen cycle across time gives scientists a better idea of how life may have evolved.

Robert Gastaldo is a paleontologist from Colby College.

There was enough wood around to provide us with a record of the wildfire that we can identify and use.

The landscape that is now Europe looked a lot different hundreds of millions of years ago and the two sites that the researchers used for their analysis were on the ancient Avalonia and Baltica continents.

The cycles of carbon and phosphorus, as well as the movement of silt on the Earth's surface, would have been greatly affected by the fires of that time. A lot of unpacking is required for a complex combination of processes.

This discovery helps in unpacking by smashing the previous record for the oldest wildfire on record by 10 million years, as well as highlighting the importance that research into wildfires could have in charting the history of Earth.

According to Glasspool, "Wildfire has been an important component in Earth-system processes for a long time and its role in those processes has been under emphasized."

The research has appeared in a journal.