Sanphodiacaulis densifolia is an extinct tree species that existed in what is now New Brunswick, Canada, between 359 and 347 million years ago (Carboniferous period). The structure consisted of an unbranched 16 cm diameter trunk and compound leaves arranged in a 13 cm spiral and compressed to a vertical trunk length of 14 cm. The compound leaves in the upper 0.75 m of the trunk were over 1.75 m long, with preserved alternating secondary collaterals starting 0.5 m from the trunk. In the lower region of the trunk there were only persistent leaf bases. Sanphodiacaulis densifolia shows that the early Carboniferous vegetation was more complex than expected, indicating that this was an experimental, perhaps transitional, period of diverse growth structures.
Trees first appeared during the Middle Devonian period (393 to 383 million years ago), but modern woody plants did not appear until about 10 million years later.
Evidence for dendritic structures (tree-like structures) is primarily based on mud moldings, sand moldings, or calcified stumps, or extensive root structures in fossilized soils.
Under unique preservation conditions, these early trees fossilized with roots and crown structures attached to their trunks.
“The method is Sanphodiacaulis densifolia “It has very long leaves around its slender trunk, and it's amazing how many leaves there are on such a short trunk,” said Dr. Robert Gastaldo, a paleontologist at Colby College. he said.
“The morphology of these 350-million-year-old trees looks like ferns or palms, even though palms arose 300 million years ago.”
“However, the functional leaves of ferns and palm trees are clustered at the top and are relatively few in number.”
“in contrast, Sanphodiacaulis densifolia More than 250 leaves have been preserved around the trunk, with each partially preserved leaf extending 1.75 meters from the trunk. ”
“We estimate that each leaf grew at least another meter before it finished.”
“This means that ‘bottlebrush’ had a dense canopy of leaves that were not woody and spread for at least 5.5 meters around a trunk that was only 16 cm in diameter. Amazing to say the least. .”
Sanphodiacaulis densifolia It has compound leaves arranged in a spiral.Image credit: Gastaldo other., doi: 10.1016/j.cub.2024.01.011.
Dr. Gastaldo and his colleagues examined five fossil specimens. Sanphodiacaulis densifolia.
The fossil was excavated from the Sanford Quarry, part of the Albert Formation in New Brunswick, Canada.
“These fossils were preserved when an earthquake destroyed trees and other vegetation along the edge of a rift lake,” Gastaldo said.
“The first fossil wood was unearthed from a quarry about seven years ago, but it contained only one partial sample.”
“It took several years to find four other specimens of the same plant in close spatial proximity.”
“One of the specimens reveals how the leaves separate from the top of the tree, which makes this tree quite unique.”
“This is one of the few preserved trunks with crown leaves still attached in a fossil record spanning more than 400 million years.”
Actual and reconstructed heights and biostratigraphic ranges of Pennsylvanian trees from the Middle Devonian. Image credit: Gastaldo et al., doi: 10.1016/j.cub.2024.01.011.
Sanphodiacaulis densifolia It probably relied on its unusual growth form to maximize the amount of light it could capture and reduce competition with other plants above ground.
This discovery provides important insights into the evolution of plants and arboreal growth, that is, plants that grow to the height of a tree, or at least 4.5 m, at maturity.
They also remind us that throughout the history of life on Earth, there have been trees that look like nothing we've ever seen before.
“We all have a mental concept of what a tree looks like, depending on where we live on the planet, and we all have a vision of something familiar,” Dr. Gastaldo said. Ta.
“The fossils we report are unique and represent some of the strangest growth forms in the history of life.”
“This is an evolutionary experiment during a period of forest plant biodiversity, and it appears to be a short-lived form.”
“The history of life on land consists of plants and animals that are different from those that live today,” he added.
“The evolutionary mechanisms that operated in the distant past allowed organisms to survive for long periods of time, but their shape, morphology, growth structure, and life history followed different trajectories and strategies.”
“Rare and unusual fossils like the New Brunswick tree are just a few examples of failed experiments that have colonized our planet.”
a paper The survey results were published in a magazine current biology.
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Robert A. Gastaldo other. A mysterious fossil plant with a three-dimensional tree-like growth structure from the earliest Carboniferous period in New Brunswick, Canada. current biology, published online on February 2, 2024. doi: 10.1016/j.cub.2024.01.011
Source: www.sci.news
