A rare 3D fossil of trees older than dinosaurs reveals strange, alien-like ancient forests
It’s hard to imagine the Earth without its forests, but it wasn’t until the Devonian Period just 400 million years ago that the first strange tree-like fluff emerged from Earth’s pubescent chin.
What little we know about critical periods of ancient arborescence, or tree evolution, is based mostly on tree trunks and roots preserved in rock, with leaves and branches scattered flat between layers of clay and stone.
A 2.3-metre (7.5 ft)-long and about 2-metre-wide stone block stored at the New Brunswick Museum in Canada contains some remarkable exceptions, giving researchers a 3-D view of an ancient species that appeared only about 15 million years after the first tree. Like plants appeared.
The block was excavated from a New Brunswick quarry in 2017 by Museum of New Brunswick paleontologists Olivia King and Matthew Stimson, and it preserves the remains of five branching plants growing nearby, presenting the arrangements of their upper leaves in curious detail.
“The way this tree produced very long leaves around its slender trunk, and the sheer number along the short trunk, is astonishing,” says Robert Gastaldo, a geologist from Colby College in the US who led the investigation into this fascinating phenomenon. Fossil.
Although palm trees would not appear for another few hundred million years, the plant’s elongated, radiated leaves are currently classified as palms. Sanfordiacolis densifolia It has a passing resemblance to something you find in the desert or on a tropical island. Albeit a painful alien.
As the Devonian Period gave way to the Carboniferous Period, plants we might vaguely recognize as conifers, cycads, and ginkgos appeared and spread. Identifying the more obscure plants of the period based on a few details is much more difficult.
“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,” Gastaldo says.
“The fossil we report is a unique and peculiar growth form in the history of life. It is one of the experiments in evolution during a period when forest plants underwent biodiversification, a form that appears to be short-lived.”
The small orchard, which supposedly grows beside a lake in an earthquake-prone area, is believed to have been choked by an earthquake that buried plants and other nearby vegetation in soft mud.
Researchers estimate that its height can reach nearly 3 metres, if not higher, with a thick arrangement of leaves extending 2 to 3 meters from the trunk to form a dense foliage volume at the crown of up to 30 square metres.
Like many similar trees that compete for light under dense forest canopies, Sanfordiacolis They may have evolved bottlebrush anatomy to eliminate as much radiation as possible while being dwarfed by larger plants.
Such primitive examples of long-extinct plants evolving as ecosystems experience new environments and conditions to survive give researchers a clearer picture of the kind of trial-and-error approach evolution takes.
“Evolutionary mechanisms operating in the deep past led to organisms that lived successfully over long periods of time, but whose shapes, forms, growth structures, and life histories took different paths and strategies,” says Gastaldo.
“Rare and unusual fossils, like the New Brunswick tree, are just one example of something that colonized our planet but was an unsuccessful experiment.”
This research was published in Current biology.