A paper published last week in the journal Current Biology opens a window into the plant world during the Carboniferous, when New Brunswick was a tropical land about 10 degrees from the equator.
The plant dates back to a time of change when plants and animals began to adapt and diversify on Earth, said Matt Stimson, one of the study’s authors, who works at the New Brunswick Museum in Saint John.
The tree was a “failed evolutionary experiment” and did not survive, but he said it helps researchers understand the complexity of forests. He added that finding an intact fossilized tree is unusual.
“This is very rare – it’s so rare, only a few have ever been found in…the entire fossil record,” he said. “Not only at this time, but anywhere in geological time, where the trunk, branches and leaves are connected and complete.”
The fossil was found in 2017 in a quarry in Norton, New South Wales, about 80 kilometers southeast of Fredericton. Before publication, he said, researchers had to verify their discovery and ensure that the science was accurate and that they had actually discovered something completely new.
“Ultimately, science takes time. Big claims require big evidence.
Stimson said he was doing summer fieldwork with Olivia King, a graduate student at Saint Mary’s University, when they saw a large stone that appeared to be discolored, and they began gently digging around it. Then the more than 300 million-year-old fossil preserved in a two-ton rock began to reveal itself — a spiral formation of leaves attached to the stem.
The area where the fossil was found was a lake bed, located on a fault line, when the tree grew. Stimson said an earthquake tore down the tree and buried it in layers of sand.
Another unique thing about the fossil is that it was preserved in a 3D-like state, said Adrian Park, a co-author of the paper who works for the New Brunswick Department of Natural Resources.
“Normally, a tree falls and gets buried in the mud,” he added. “This mud is embedded in a rock, and the fossils are then compressed in the process into a single layer, onto a flat surface.”
“In this case, the branches actually break through the layers. And the layers themselves are very twisted. …The sand flowed very quickly from the top and kept it in three dimensions.”
He said the tree, which he named Sanfordiacaulis densifolia, after the quarry where it was found, had a smooth trunk 16 centimeters long, was three meters high, and had a “bottle brush” canopy of 250 leaves, each about 1.75 feet long. meter.
Stimson described it as a “giant plant” rather than a tree.
“They were like giant ferns or very strange trees that looked like Dr. Seuss trees, very different from anything today,” he said, referring to the beloved children’s book author’s illustrations.
“The branches or leaves come directly from the trunk and are in a spiral pattern coming out horizontally from the tree… in a very dense manner.”
This structure would have allowed the tree to capture as much sunlight as possible after it moved through the upper and middle canopies of the forest to ground level where smaller shrub plants of its kind sit, Stimson said.
He said that this plant tells us what the forest was like at that time. There are not many plant fossils from this period on Earth, known as the Romer’s Gap. He added that although this plant was a failed experiment, the plants that survived are the ancestors of today’s forests but in a much different form. Mosses, for example, were up to 30 meters high during the Early Carboniferous, but are now only a few centimetres, he said.
He added that the Carboniferous period in which these trees were found was also a transitional period when the swamps were teeming with life, including ferns with spores, millipedes and giant salamander-like creatures that began crawling out of the water.
“These early forests housed and provided habitat for the first amphibians that moved from water to land. “You certainly wouldn’t want to swim in the water,” Stimson said. “There were giant sea scorpions, very large fish with teeth… and millipedes And other types of insects crawl on the ground.”
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