First record of chambered hexactinellid sponges from the palaeozoic

Abstract

A new chambered hexactinellid sponge, Casearia devonica sp. nov., is described from the Lower Devonian of northern Spain (Cantabrian Mountains). The fossil represents the first evidence of chambered hexactinellid sponges from the Palaeozoic and the oldest representative of the order Hexactinosida. Casearia devonica sp. nov. occurred within small metre-sized mud mounds that developed in deeper water below the storm wave base.