Distinguishing Pennsylvanian-age lowland, extra-basinal and upland vegetation

The distribution of plant fossils and their palaeoecology inDuckmantian(Bashkirian, Lower Pennsylvanian) strata atBrymbo, North Wales, UK

“…In the Ruhr, however, the species are more widely distributed in the Horster Schichten. Similar‐aged floras also occur in the upland‐wetland basins ( sensu Thomas & Cleal, ) of Euramerica, such Saar‐Lorraine (e.g., Laveine, ) and Western and Central Bohemia (e.g., Šimůnek in Pešek, ), but these tend to have very distinctive floras from those of the lowland paralic basins such as seen at Brymbo (e.g., Cleal, , ).…”

“…In the Ruhr, however, the species are more widely distributed in the Horster Schichten. Similar-aged floras also occur in the upland-wetland basins (sensu Thomas & Cleal, 2017) of Euramerica, such Saar-Lorraine (e.g., Laveine, 1989) and Western and Central Bohemia (e.g., Šimůnek in…”

“…Álvarez‐Vásquez and Wagner () added the comment that “the shape and size of the leaf scar to be due to the position of the leaf with regard to the leaf cushion and to the kind of leaf base, which may be either narrow or more laterally extensive.” We believe that the line near the top of the leaf cushion would be better described as a “false leaf scar” as done by Chaloner (, , , p. 533) because many leafy stems lose their laminae when the rock is split. It is most likely that all parts of arborescent lycophytes were originally leafy and only when the taller, maturing plants started to branch that their lower parts would have been shaded, with a subsequent reduced ability to photosynthesize, prompting the loss of leaf laminae (Thomas & Cleal, ).…”

“…We believe that the line near the top of the leaf cushion would be better described as a "false leaf scar" as done by Chaloner (1986aChaloner ( , 1986bChaloner ( , 1967) because many leafy stems lose their laminae when the rock is split. It is most likely that all parts of arborescent lycophytes were originally leafy and only when the taller, maturing plants started to branch that their lower parts would have been shaded, with a subsequent reduced ability to photosynthesize, prompting the loss of leaf laminae (Thomas & Cleal, 2017).…”

The floristic relationship between the upland and lowland Carboniferous wetlands of Variscan Euramerica — Evidence from some medullosalean pteridosperm fronds

“…2. 2 What were the upland wetlands? Thomas and Cleal (2017) recently discussed what palaeobotanists have meant in the past when using the term upland floras. It became clear that most so-called upland floras were not upland in any meaningful sense; the term was instead mainly being used to refer to vegetation of dryland or better drained lowland habitats.…”