Fossils of a rare 350-million-year-old tree found – why it's so unique to scientists

Rare tree fossils dating back 350 million years and preserved by their leaves have a structure that scientists have never seen before, a study has shown.

The well-preserved fossils belong to some strange shrub trees discovered in southeastern Canada. The ancient trees are unlike anything scientists have ever seen, and may be examples of an experiment in evolution.

earthquake before 350 million years Cut down these trees and bury them in the mud. This resulted in almost perfect impressions of their trunks and leaves being preserved in the sediments at the bottom of the lake at that time. Geologists discovered the first fossilized tree in A quarry was dug in New Brunswick in 2017; Then they discovered four more nearly identical samples.

“We were shocked. It is an anomaly to find a tree-sized fossil plant that retains its leaves [και] It is attached to the stem in the form of a crown, said Colby College geology professor emeritus and lead study author Robert Gastaldo.

Because it is unique to scientists

Usually, only ancient tree trunks are preserved in the fossil record. The new discovery reveals a dense canopy of leaves comprising more than 250 leaves clustered around the 75cm-tall top of a long, slender, branchless tree trunk, about 2.7m tall.

The leaves are up to 3 meters long and extend from the stem to “Tightly compressed files”, According to the study published in the journal Current Biology.

The trees, named Sanfordiacoulis, likely developed this spiral arrangement to maximize the amount of sunlight absorbed by the leaves for photosynthesis, according to the researchers.

Their smaller height indicates that these Plants are the oldest example of small trees It grows under tall trees in the forest.

Rebuild these plants “It distorts our sense of how trees are organized and grow. Their growth structure is similar, but distinctly different from two typical trees found in the tropics today.” Robert Gastaldo noted.

The strange fossils are attributed to an experiment in the evolutionary process

Typical trees found in the tropics today are few in number From ferns, gymnosperms (plants with exposed seeds) and flowering plants. The geology professor added that these modern plants contain a smaller number of leaves in their crown, about 15 to 20 genera in the case of ferns and palms.

the Sanfordiacolis Perhaps it stood out among its plants Lithanathracoferous period (359 million to 299 million years ago), as quiver trees (Aloiendron dichotomum, formerly Aloe dichotoma) and baobabs (Adansonia) do today, Gastaldo said.

“We think these are exotic compared to other angiosperms [ανθοφόρα φυτά]. Such deviations were present very early in other groups of plants that lived long before flowering plants appeared on the planet. “But we have no evidence of their peculiarities, unless a very rare event occurs to preserve the plant as a whole.” The geology professor noted.

Plants diversified greatly during Devonian era (419 million to 359 million years ago) and in Carboniferous periodaccording to the study.

Gastaldo said the strange fossils may be an example of an evolutionary experiment from that time that ultimately failed. “The evolution of the plant kingdom has undergone many different experimental forms that have been successful for a few million years or more. But they have not stood the test of time.” The geology professor concluded.