Résumé
Silicified tree trunks are described for the first time from Montford, near Rothesay, Isle of Bute, Scotland. The fossils occur in a fault-bounded succession, which is probably part of the Mississippian (Courceyan) Kinnesswood Formation. Quantitative anatomical analysis indicates that the tree trunks belong to the arborescent pteridosperm, Pitus primaeva Witham. Growth interruptions preserved in branches imply that these trees experienced aperiodic water stress, perhaps reflecting monsoonal seasonality in this part of palaeoequatorial Laurasia