A revision of the Carboniferous lungfish genus Ctenodus is undertaken. Ctenodus is the longest-surviving genus of lungfish from the Carboniferous, and is the only one to cross the Lower–Upper Carboniferous boundary. Five species span the period, with species correlated to stage. Species are distinguished by differences in tooth plate morphology. Ridge number increases from the Tournaisian to the Moscovian, and the length to width ratio decreases. A new, almost complete articulated individual of C. interruptus allows identification of this species from pterygoid tooth plates and other characteristics. These, and new features of the postcranial skeleton, are described for the first time. Ctenodus retains primitive features of the skull roof, such as a pair of C-bones and retention of a D-bone; its contemporaries Conchopoma, Sagenodus and Straitonia show the derived condition of these features. Ctenodus retains primitive features of the lepidotrichia, which are distally segmented and bifurcated. However, it also shows the derived condition of the tail region in having a combined first and second dorsal fin: whether there was a separate caudal fin remains unknown.

Mudstones above coals in the eastern part of the South Wales Coalfield have yielded diverse and well-preserved palynofloras. They indicate that the Llantwit No. 1 and No. 2 seams are Stephanian in age, and thus correlate with the Household Coals Member in the Forest of Dean. Until the formation of the highest coal seam in the succession (No. 1 Llantwit Seam), conditions were progressively becoming wetter, as indicated by an increase in abundance of lycophytes and a decline in the cordaites. However, after the formation of this stratigraphically highest coal, the lycophytes declined significantly, indicating that conditions suddenly became drier, perhaps as a result of uplift of the area as the Variscan Front to the south steadily pressed forward.