Abstract For the biostratigraphy of mixed continental-marine and purely continental sections in the palaeotropical belt of Euramerica, 9 insect and 8 conchostracan zones are newly defined or improved. These zones encompass the time interval from the Early Pennsylvanian (middle Bashkirian) up into the early Permian (early Asselian) of the Euramercian biotic province. They are linked as much as possible to the marine Standard Global Chronostrigraphic Scale by common occurrences of insects and/or conchostracans with conodonts in mixed marine-continental sections as well as by the thus far available and reliable radioisotopic ages of associated volcanic rocks. This insect and conchostracan zonation is an alternative tool to the well-established macro-plant biostratigraphy of the Pennsylvanian. In contrast to the latter, only single specimens of insects or conchostracans, even if more rare than plant remains, allow biostratigraphic dating with a similar high temporal resolution.

In paleoequatorial parts of Europe and North America, late Paleozoic cyclic successions are widely inferred to reflect glacio-eustasy. However, many of these successions accumulated in basins in the Pangean collisional zone, where variations in tectonics and sediment supply could also have generated cyclic successions. Cyclic successions are ubiquitous in the Maritimes Basin of Atlantic Canada but are especially prominent in the Visean and Bolsovian to Cantabrian, when subsidence rates on coastal plains were low and probably steady during periods of thermal subsidence. During relatively humid climatic conditions in the Bolsovian to Cantabrian, fluvial systems generated clastic cyclic successions with deep valleys and mature interfluve paleosols, providing strong evidence for alternate rise and fall of sea level—a characteristic glacio-eustatic feature. Under arid conditions in the Visean, with few rivers, carbonate-evaporite rhythms formed with little evidence for incision. Comparisons with near- and far-field records for Gondwanan glacial activity suggest that these two periods correspond to sea-level changes on the order of a few tens of meters, probably due to melting and accumulation of small ice caps rather than continent-wide ice sheets. Cyclic successions that formed in basins undergoing steady thermal subsidence may provide the most reliable evidence for glacio-eustasy in the paleoequatorial realm.

Abstract The 13 presently known genera of Late Devonian tetrapods are situated in the recently completed miospore zonation of Western Gondwana and Euramerica, in relation to the standard conodont zonation. Some of them are still unprecisely dated. The stratigraphic sequences of East Greenland, North China and East Australia are briefly reviewed to discuss the age of the tetrapods collected there and to analyse consequences in relation to the Frasnian–Famennian and Devonian–Carboniferous boundaries. Two episodes of biodiversification seem to have occurred: the first in the Frasnian and the second in the late and latest Famennian. Due to the currently known fossil evidence, the consensus scenario advocates a late Middle Devonian to early Late Devonian origin of tetrapods on the Old Red Sandstone Continent (Euramerica) at a time of warm climate and recovering atmospheric oxygen level during the building of a pre-Pangaean configuration of landmasses.