The echinoid fauna from the Campanian rocky shoreline at Ivö Klack in Sweden is described taxonomically; it includes 16 taxa, comprising three cidaroids, one diadematoid, two phymosomatoids, four saleniids, two holectypoids, three cassiduloids, and a single holasteroid. Of these, Tylocidaris (Tylocidaris) imbricata, Hirudocidaris botryoformis, H. zeamays, Trochalosoma ivoensis, Globator schroederi and Scaniosoma (n. gen.) surlyki are new. These taxa are interpreted to represent three distinct ecological groups; of these, one was adapted to living epifaunally on boulders, one epifaunally in crevices and the third shallowly buried in shell sands and gravels. The present study is based on material picked from residues of a large (500 kg) bulk sample from the upper part of the succession, and examination of historical collections.
Within the upper Paleocene (Thanetian) flysch conglomeratic sandstones of the Magura Nappe, a bed characterized by dominant coralline red algae, with subordinate benthic foraminifera, corals, bryozoans, and molluscs has been identified. It is the only known site showing evidence of rarely explored Paleocene shallow-water areas in the Magura Basin. Corallines occur as abraded coralline algal debris and rhodoliths. The upper Paleocene coralline algal debris consists of rounded, sand- to pebble-size clasts. Two types of rhodoliths were distinguished: abraded sub-spheroidal boxwork up to 0.5 cm in diameter, and irregular boxwork rhodoliths larger than 1 cm in diameter. In the coralline algal assemblage, the most abundant component is Sporolithon sp., with subordinate Lithothamnion sp. and Mesophyllum sp. Karpathia sphaerocellulosa and Spongites sp. are also present. Bioerosions, such as Entobia isp., Gastrochaenolites isp., Trypanites isp., and microborings are common in the coralline debris. This assemblage documents the shallow-water carbonate biogenic sedimentation in the northern Magura Basin during the Thanetian. These corallines formed above the storm wave base and were redeposited offshore in the inner part of the Magura Basin by sediment gravity flows.