Stigmaria - imprint of fossil root in sandstone

3D Model

In Northumberland (UK), where these fossils are fairly common, particularly as fossil imprints on the surface of sandstone outcrops (where the actual fossil has eroded out), we call them “mountain bike tyre tracks”.

They are usually known by the name Stigmaria and are the fossilised roots of now extinct, large (up to 30-50m) tree-like plants of the Carboniferous (300 million years old) also known as lycopods, similar to present day club mosses. Fossils from parts of the plants normally above ground are called Lepidodendron or Sigillaria (as is the fossil tree from the coal measures in Stanhope churchyard). https://www.geograph.org.uk/photo/1270025

Commonly found in Northumberland sandstones and shales as imprints or actual fossil pieces. Fossilised roots are apparently more common than above ground parts as they were already buried in the sand.

There is a nice description here: http://www.uky.edu/KGS/fossils/fossil-month-Stigmaria.php

See a model of Stigmaria fossil root here: https://skfb.ly/6RHOH