Light micrograph (transverse section) of fossil wood from one of the first forest trees Callixylon newberryi. The sample was found in New Albany shale

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Light micrograph (transverse section) of fossil wood from one of the first forest trees Callixylon newberryi. The sample was found in New Albany shale from the Upper Devonian period in Indiana, USA. These first forest trees, known as progymnosperms, are ancestral to the living gymnosperms (see B500/056 for living example) of which the most familiar are the conifers. Nomarski differential interference contrast, magnification X40 (at 35mm size).

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Size: 5299px × 3522px
Photo credit: © SINCLAIR STAMMERS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ancestor, callixylon, fossil, fossils, gymnosperm, newberryi, palaeontology, paleontology, plant, plants, progymnosperm, wood