• The community occurs in siliceous nodules in silty shale of the Bádenas Formation. The high diversity (at least 19 species belonging to 11 genera) of bivalves indicates generally favourable living conditions for these taxa. Small juvenile cephalopods are commonly current orientated. The occurrence of infaunal, semi-infaunal, reclining and epibyssate bivalves is characteristic of a soft bottom environment with favourable biotic conditions on the substrate–water interface and slightly above the bottom. The sea bottom below wave base was almost continuously well ventilated by low current activity (2.6% of shells with conjoined valves preserved). Infaunal (37 per cent) and semi-infaunal (47% species are dominant, reclining (5.3% and epibyssate species (10.5%) are subdominant. Most common are small adult valves of the semi-infaunal Actinopteria dakryodes (59.9% of individuals), whose abundance indicates favourable conditions such as nutrient supply in suspension transported into the environment by current activity. Larger shells of the subdominant (second in rank abundance) infaunal species Copenychia franta (6.6% of individuals) support the possibility of slightly better conditions for infaunal species. The lack of deposit feeders probably reflects a lack of particular nutrients or the presence of abiotic conditions within the sediment. In general the community indicates restricted conditions (generally low oxygen content) not favourable for other groups of organisms, e.g. brachiopods, trilobites, crinoids and even gastropods. The common occurrence of eurypterids should not be used as an indicator of depositional environment (Plotnick 1999). The common occurrence of orthocone cephalopods, including their juvenile stages, indicates normal salinity in the environment above the sea-floor.

• ... the Bádenas Formation comprises black silty shale of the Oktavites spiralis Biozone, occurring in several exposures. The uppermost levels are remarkable for the abundance of decalcified fossiliferous siliceous nodules. They contain common bivalves, orthocone cephalopods and abundant eurypterids, which have not yet been systematically studied. Only graptolites from this locality have been reported in the past by several authors; these were listed by Gutiérrez-Marco and Storch (1998) and revised by Storch (1998). Additional fauna includes peltocarids, cornulitids, rare brachiopods and very rare trilobites.