Recent changes along the margins of the Antarctic Peninsula, such as the collapse of the Wilkins Ice Shelf, have highlighted the effects of climatic warming on the Antarctic Peninsula Ice Sheet (APIS). However, such changes must be viewed in a long-term (millennial-scale) context if we are to understand their significance for future stability of the Antarctic ice sheets. To address this, we present nine new cosmogenic 10Be exposure ages from sites on NW Alexander Island and Rothschild Island (adjacent to the Wilkins Ice Shelf) that provide constraints on the timing of thinning of the Alexander Island ice cap since the last glacial maximum. All but one of the 10Be ages are in the range 10.2–21.7 ka, showing a general trend of progressive ice-sheet thinning since at least 22 ka until 10 ka. The data also provide a minimum estimate (490 m) for ice-cap thickness on NW Alexander Island at the last glacial maximum. Cosmogenic 3He ages from a rare occurrence of mantle xenoliths on Rothschild Island yield variable ages up to 46 ka, probably reflecting exhumation by periglacial processes.

Until now hemispherical astylospongiid sponges were invariably referred to as Caryospongia juglans var. basiplana Rauff. Renewed investigations have now shown that part of the material should be assigned to a new genus and species, Tympanospongia vankempeni, which is characterised by a system of very irregular canals. These flat-based sponges originate from the Baltic region and occur in two assemblages of silicified Late Ordovician sponges known exclusively as erratics from The Netherlands and northern Germany. These fossils were transported by the River Eridanos, a former drainage system from the Baltic region that filled the North European Basin during the Miocene to Early Pleistocene. Specimens of Tympanospongia vankempeni gen. et sp. nov. also occur in the Upper Pleistocene of Gotland, Sweden. The new sponge described herein principally differs from other genera of the Astylospongiidae found frequently in the erratic sponge assemblages by its irregular system of apochetes which ramify and anastomose commonly.

Compound orchocladine sponges are unusual in the Early Palaeozoic. In Europe, silicified material of Late Ordovician age has hitherto been referred to as Aulocopium aurantium Oswald, 1847 and the invalid Aulocopium compositium Conwentz, 1905. An examination of new material has resulted in the recognition of a new genus, Hydraspongia, with two new species, H. polycephala and H. erecta, and a third new species, Perissocoelia megahabra, to which most specimens can now be assigned. These taxa form part of rich erratic sponge assemblages, which originate from unknown source areas in the Baltic, and have been collected in northern and western Europe from fluvial sandy deposits of the Eridanos River system, which drained the Baltic area from the Middle Miocene to Early Pleistocene.