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- I show some finds of fossil Devonian fungus "Prototaxites"
Happy new year everybody!
Last year I learned about a fascinating enigmatic fossil from the Silurian and Devonian, maybe even Ordovicium, which bears the name "Prototaxites".
The name was given to it already in the 19th century as it resembles logs of petrified wood up to 8m tall.
It is quite fascinating that, at a time where land plants where at best lousy little shubs, mushrooms as high as trees dominated the landscape.
For the next 100 years or so it was considered to be an algae like kelp, although there were plenty of observations that it was probably living on land. Latest since 2000, it became consensus that it has fungal affinity, or was maybe a lichen.
See the Wikipedia article.
It turns out that it is not even particularly rare. I collected some on a field near the former German capital Bonn, some are shown here:
Characteristic surface structures are clearly visible, as well as a characteristic zonation, similar to the annual rings seen in wood.
In one piece cut through, a burrow, probably from an arthropod, is clearly visible.
The material is silicified, and sometimes quite well preserved so that even microscopic details become visible in thin sections:
One recognizes the hyphae and brown "cortical" spots, which may be related to nests of an algal symbiont if the lichen hypothesis is true.
Between crossed polars, it even looks artistic.
It turns out that it is not only widespread in Europe, but also in the new world. The first description is from Gaspé, Kanada, but a famous sample, the so called Schunnemunk tree is from Monroe, New York. So maybe someone in this forum also has some pieces?
Last year I learned about a fascinating enigmatic fossil from the Silurian and Devonian, maybe even Ordovicium, which bears the name "Prototaxites".
The name was given to it already in the 19th century as it resembles logs of petrified wood up to 8m tall.
It is quite fascinating that, at a time where land plants where at best lousy little shubs, mushrooms as high as trees dominated the landscape.
For the next 100 years or so it was considered to be an algae like kelp, although there were plenty of observations that it was probably living on land. Latest since 2000, it became consensus that it has fungal affinity, or was maybe a lichen.
See the Wikipedia article.
It turns out that it is not even particularly rare. I collected some on a field near the former German capital Bonn, some are shown here:
Characteristic surface structures are clearly visible, as well as a characteristic zonation, similar to the annual rings seen in wood.
In one piece cut through, a burrow, probably from an arthropod, is clearly visible.
The material is silicified, and sometimes quite well preserved so that even microscopic details become visible in thin sections:
One recognizes the hyphae and brown "cortical" spots, which may be related to nests of an algal symbiont if the lichen hypothesis is true.
Between crossed polars, it even looks artistic.
It turns out that it is not only widespread in Europe, but also in the new world. The first description is from Gaspé, Kanada, but a famous sample, the so called Schunnemunk tree is from Monroe, New York. So maybe someone in this forum also has some pieces?
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