Devonian progymnosperm wood charcoal from Cottonwood Canyon, Wyoming


Charcoal collected by Mihai Tomescu along the Souris river at Cottonwood Canyon, Wyoming, USA in 2017 showing diagnostic features typical of progymnosperm wood: clustered pits in the tracheids. Notice how the pits are closely clustered, and the tracheids are smooth between the pit clusters. This compression was collected from Devonian sediments roughly 400 million years old, give or take 20 million years. No chemical fixation. Sputter coated in gold about 320 atoms thick. Working distance 25.5 mm, backscatter electron detector, accelerating voltage 30 kV, spot size 4.0, scale bar 50 µm, magnification 1,250X, Quanta 250 electron microscope.

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