Giant mushrooms 7 m high once dominated the earth

When terrestrial plants are still “rookies” in the evolution process and the tallest trees in the world only reach about 1 m, there are mysterious creatures protruding from the ground like a giant pillar. Their fossils dating from 350 million to 420 million years, including body tall as 7 m and 1 m wide.

The scientists first discovered this strange fossil in 1843 and felt confused. Initially, in 1859, they described them as plants in the pine industry.

However, experts discovered these huge spinals, today called Prototaxites, not made of wood. They come up with many other ideas about their identity such as kelp, the fruits of mushrooms or even lichen. The debate has lasted more than 150 years.

“The problem is that when looking closely at the anatomical structure, they are reminiscent of many different things, but do not diagnose anything specific,” said Kevin Boyce, an expert at Stanford University. Another problem is the size.

Today, most scientists accept prototaxites as mushrooms. Boticians of Francis Hueber at the Smithsonian National Museum of Natural History have made great contributions to this. He made the internal structure map of the fossil and found their anatomical structure more like mushrooms than plants. But he has not found convincing evidence to prove.

After that, Huuber’s 2007 study, Boyce and his colleagues found a value evidence by chemical analysis. They check the ratio of carbon-12 and carbon-13 isotopes in Prototaxites fossils. If this mysterious creature is a plant, that ratio will match other plants at the same time, because all take carbon from the same atmosphere through photosynthesis.

Instead, the team found that this rate was significantly different from plants, supporting mushroom hypotheses. Thus, Prototaxites can be like giant mushrooms, although they look like any kind of mushrooms today.

If they are really primitive, they may not have any descendants who are still alive, according to Boyce and Ecologist Matthew P. Nelsen. But through their fossils, people imagine a long -lived world, where Prototaxites may have rising higher than everything else. “They created in my mind one of the most strange prehistorical landscapes,” said the ancient artist Kirk Johnson, director of the National Museum of Natural History Smithsonian.