3D model of the fossil stem of a giant lycopsid plant (NHMW-GEO-2024/0188/11041)

<p>This is the fossil stem of a giant lycopsid plant and is a species of <i>Knorria</i>. Lycopsids are related to ferns, so they produce spores rather than seeds.&nbsp;Today, they are all very small plants, inhabiting moist areas of forest understoreys. But, during the Carboniferous Period, lycopsids were the largest trees on the planet, with some growing more than 40 m tall!&nbsp;This particular fossil is a species of <i>Knorria</i>, which represents the fossil stems of large lycopsid trees where the outer tissue has been shed, leaving only a surface impression on sandstone. This style of preservation is particularly common in these Carboniferous lycopsid trees, since they did not develop robust wood throughout their trunks, like modern trees do. Hence, the inner parts degrade relatively fast and fill up with sediment, while the outer surfaces resist this degradation longer, retaining the overall 3-dimensional shape.</p><p>This object is part of the historical ‘Ettingshausen collection’, which is on permanent loan from the Institute of Biology, University of Graz.</p>