A plant-root system in the Lower Devonian of the Holy Cross Mountains, Poland

The depositional environment of the Lower Devonian of the Holy Cross Mountains has only been studied and interpreted in part, particularly for the lower portion of the profile. Recent fieldwork findings suggest a considerable change with regard to earlier hypotheses. Apart from the sedimentological observations that indicate marginal marine and very shallow-water conditions, horizons with plant-root traces and layers interpreted as palaeosols showing different stages of pedogenesis have been documented. The presence of palaeosols in some areas of the Holy Cross Mountains is the first direct evidence for the existence of terrestrial conditions during the Lower Devonian in this area. This plant-root system is one of the oldest fossil records ever described globally.