The Fossil Grove is on a by floor of an old quarry, and belongs to the same geological time period as several other groups of
Lepidodendron fossils found northwest of
Glasgow. The stumps themselves are
internal casts of the hollow lycopsids, representing the huge
cortical meristem of the lycopsids rather than the woody interior. The remnants of trunks belonged to
Lepidodendron veltheimianum lycopods and the underground systems are called under the form taxon,
Stigmaria. The common species of
Stigmaria ficoides were discovered from the site. The sandstone in the Grove is covered with shale that was deposited as mud in a major flooding episode, and this deposition of sediment knocked over and killed the lycopsids. The soft tissues of the cortical meristem and inner
phelloderm of the lycopsids then decomposed and made the lycopsid and their underground systems hollow, and subsequent flood waters filled the hollow lycopsid stumps with sand. Ripple marks on some surfaces indicate a south-western flow of the flood waters. The trunks were then buried and
lithified, and became molds in the surrounding sandstone. The sand inside the trunks became solid rock, and the outer bark of the lycopsids became a thin layer of coal. Though some trunks are elliptical, especially the tallest,
Lepidodendron lycopsids were typically circular. The deformations were likely caused by the force of the rising flood waters that filled the trunks with sand, as indicated by the tendency for the deformations to be in the same direction as the ripple marks, towards the south-west. Besides the fossil stumps, the only other indications of organic life in the strata of the Fossil Grove are
Arenicola burrows found in some sandstone beds. ==History==