Guettardiscyphia zitti sp. n. - a remarkable hexactinellid sponge from the Lower Turonian of the Bohemian Cretaceous Basin

Abstract

This paper describes a new hexactinosidan hexactinellid Guettardiscyphia zitti sp. n. on the basis of a detailed study of 279 specimens from 12 localities in the southern part of the Bohemian Cretaceous Basin. All the studied material comes from the basal Bílá Hora Formation (Lower Turonian). The geology and palaeontology of the sponge-bearing strata at studied locations exhibit identical palaeoenvironmental settings: 1 –  transgressive character of sediments with low sedimentation rates, 2 – presence of submarine swells formed by crystalline basement, 3 – hemipelagic sedimentation below the storm-wave base, and 4 – the presence of proliferating diverse sponge faunas with subordinate accompanying macrofaunal remains.