Charred biota from an Early Cretaceous fissure fill in W‑Germany and their palaeoenvironmental implications

Evidence for palaeo-wildfires is abundant in many continental Cretaceous deposits and in general this period is considered a ‘high-fire’ period in Earth's history. This contribution presents charred meso-fossils (plant remains and coprolites), as direct evidence of palaeo-wildfire, from an Early Cretaceous fissure-fill within Devonian limestones in the Sauerland region in W‑Germany. The flora consists of rare bryophytes, abundant fern remains, unidentified herbaceous axes, wood and conifer remains, as well as insect coprolites. Fern remains (i.e. pinnule fragments and few croziers) are most abundant, whereas wood and conifer remains are comparatively rare. Many of the plant fragments were extensively colonised by fungi prior to charring, as evidenced by fungal hyphae occurring within different tissues, as well as characteristic pre-charring decay patterns in cell walls of woody tissues. The composition of the assemblage with abundant fern remains, rare wood and few conifer remains, together with the abundant occurrence of pre-charring decay, probably points to a surface fire consuming litter on the ground as the most likely reason for charring.