New fossils discovered at Bailey Quarry near Windsor, Nova Scotia, have turned out to be from the oldest pine tree on record. The fossils were found at a site originally discovered by Dr. Martin Gibling of Dalhousie University’s Department of Earth Sciences. Dr. Gibling then invited Dr. Howard Falcon-Lang of Royal Holloway, University of London, to take part in the dig and it was Dr. Falcon-Lang who discovered the pine tree fossils.
Measuring approximately seven millimetres in length, the fossils remained encased in rock inside Dr. Falcon-Lang’s cupboard for five years before he recently took a closer look at them. “It was only when I digested the rock samples in hydrofluoric acid that the tiny fossils became visible. It was incredibly exciting when I first viewed the fossils under the Scanning Electron Microscope.
The tiny fossils were incredibly beautiful. However, very quickly I also realized that they were incredibly significant,” Dr. Falcon-Lang said.
The fossils are significant for a number of reasons. First and foremost, they are the oldest known evidence of pine trees, genus Pinus, on record, dating back to the Early Cretaceous period over 140 million years ago. Secondly, researchers determined that the fossils were preserved as charcoal, supporting the contention that pine trees at even this early stage were likely adapted to fire and wildfires.
“The fossils show that wildfires raged through the earliest pine forests and probably shaped the evolution of this important tree,” Falcon-Lang says.
Modern day pine tress have two distinct strategies for dealing with fire. One is to try to withstand low-intensity wildfires by growing tall and by self-pruning lower branches so as to escape serious damage. The other is to “embrace” the wildfire by using fire’s regular occurrence to trigger the release the trees’ seed cones. Notably, the pine tree fossils turned out to have resin ducts similar to today’s fire embracers, indicating that these early pine trees likely had fire-adaptive traits.
Nova Scotia has become the site of major fossil finds over the past few years, including last year’s discovery of tetrapod fossils which helped to explain the evolution of land animals from their sea-dwelling ancestors. Tetrapods are the fish-like amphibians that first made the move from sea to land, so named for their four limb-like flippers. The discovery of tetrapod fossils at
Blue Beach near Wolfville, Nova Scotia, showed the early presence of “advanced” tetrapods -i.e., those that were anatomically more resembling of creatures of the land than those of the sea.
And last fall, fossils of some of Canada’s oldest dinosaurs -giant herbivores from the Triassic and early Jurassic periods around 200 million years ago- were found embedded in the red sandstone cliffs along the Bay of Fundy at Parrsboro, Nova Scotia.
In 2008, the Joggins Fossil Cliffs along the Cumberland County coast of Nova Scotia were officially named Canada’s 15th UNESCO World Heritage Site.
Dr. Falcon-Lang’s research was published this month in the journal Geology.