It’s official: Nova Scotia is home to the oldest known pine tree fossils in the world.
After examining the remains of charred twigs found in a gypsum quarry near Windsor, N.S., Howard Falcon-Lang, Viola Mages and Margaret Collinson—researchers in the department of Earth sciences at Royal Holloway, University of London—determined the fossils to be around 140 million years old.
This is five to 11 million years older than the oldest pine fossil on record.
The fossils were discovered by Falcon-Lang in a quarry operated by Fundy Gypsum five years ago. Surrounded by the soft mineral, the fossils were transported to the U.K. where they remained untouched while Falcon-Lang pursued other projects.
"I'm a bit ashamed now that they were stuck there all that time," said Falcon-Lang in a telephone interview with the CBC on Wednesday. "If I had known just how exciting the material was, of course I would have given it a much higher priority."
After using an acid solution to dissolve the gypsum that surrounded the fossils, Falcon-Lang established the twigs’ ages using a scanning electron microscope. The fossils, known as Pinus mundayi, are the ancestors of the modern pine tree, a significant contributor to forests in the Northern Hemisphere.
The fossils were preserved as charcoal. The trees, say the researchers in their study, are “noteworthy for (their) fire-adapted traits.”
140 million years ago, during the Cretaceous period, Earth’s climate was much warmer than it is today. Coupled with high oxygen levels, the conditions were ideal for forest fires.
Today, some species of pine trees produce cones that only germinate after being burned, meaning new trees can only seed after a fire has destroyed an existing forest. The scorched pine tree fossils are an indication that wildfires were a common occurrence in the Cretaceous period and may have shaped the evolution of the tree.
Falcon-Lang hopes the fossils will help scientists further understand why pine trees are well-adapted to fire.
The fossils range in size from seven to 20 millimetres long.
These findings were originally published in the journal Geology.