The fossil stumps are preserved as internal casts of the stumps of hollow trees in the positions in which they grew. There are 11 trees in the ‘grove’, some larger than others
Some of the stumps are elliptical and the direction of their long axes is in the same direction (NE-SW) as the current directions infered from the ripple marks – all indicating that the river currents flowed from the NE to the SW and were so powerful that they probably squashed the then-hollow stumps. For more information see Publications.
A cross-section through the Fossil House shows the dip of the bedding and a possible configuration of the dolerite sill which was intruded some 35 million years later. One of these tongues cuts through stumps 8 and 9. The latter stump was repaired after it was damaged during the Clydebank Blitz in 1941. It now has a concrete spacer replacing the igneous sill .