A three-dimensional fossil of trees older than dinosaurs reveals that the forests of 350 million years ago were strange and alien. They were part of a small forest that was buried after an earthquake.
Trees are an essential part of life on Earth, but they weren’t always here. The first trees appeared about 400 million years ago, in the Devonian period, when plant life began to diversify and colonize land.
However, the trees of that time were very different from those we know today, and we have little information about their shape and structure, since most of the fossils that are preserved are only trunks and roots, with some leaves and branches crushed between layers of rock.
But now, a team of researchers has discovered a rare fossil that shows a three-dimensional view of an ancient tree species that sprouted about 15 million years after the first trees.
The fossil, which is found in a 2.3 meter long by 2 meter wide block of stone, is kept at the New Brunswick Museum in Canada, and was extracted from a New Brunswick quarry in 2017 by paleontologists at the museum Olivia King and Matthew Stimson.
The block preserves the remains of five branching plants that grew in close proximity, showing the arrangement of their upper leaves in astonishing detail.
“The way this tree produced enormously long leaves around its thin trunk, and the sheer number of them on a short stretch of trunk, is astonishing,” Explain Robert Gastaldo, a geologist at Colby College in the United States who led the research on the fossil. The study was published in the journal Current Biology.
Although palm trees would not appear until a few hundred million years later, the elongated, radiant leaves of the plant, currently classified as Sanfordiacaulis densifolia, bear a superficial resemblance to something you would find in a desert or a tropical island. Albeit with a disturbingly alien appearance.
As the Devonian gave way to the Carboniferous, plants that we might vaguely recognize as conifers, cycads, and Ginkgo emerged and proliferated. However, it is more difficult to get an idea of the most enigmatic plants of the period, based on scant details.
strange way of life
“We all have a mental concept of what a tree looks like, depending on where we live on the planet, and we have a vision of what is familiar to us,” adds Gastaldo.
“The fossil we report on is unique and shows a rare growth form in the history of life. It is one of the experiments in evolution during a time when forest plants underwent biodiversification, and it is a form that appears to be Of short duration”.
The small grove, which presumably grew next to a lake in earthquake-prone territory, is believed to have been buried due to an earthquake that buried nearby plants and other vegetation in fine mud.
The researchers estimate that the height of these trees could reach almost 3 meters, if not more, with a thick arrangement of leaves that extended 2 to 3 meters from the trunk to form a dense volume of foliage in the crown of up to 30 meters. squares.
The three-dimensional fossil offers a unique insight into the morphology of trees dating back 350 million years, and could help us better understand the evolution and ecology of the first land plants, the researchers say.
It also reminds us that life on Earth has taken incredible and diverse forms throughout its history, and that there is still much to learn about our plant past.
Enigmatic fossil plants with three-dimensional, arborescent-growth architecture from the earliest Carboniferous of New Brunswick, Canada. Robert A. Gastaldo et al. Current Biology, February 02, 2024. DOI: https://doi.org/10.1016/j.cub.2024.01.011