A new atrypid brachiopod, Desquamatia macroumbonata sp. n., from the Middle to Upper Devonian boundary beds of the Holy Cross Mts

Abstract

The atrypid brachiopod Desquamatia macroumbonata sp. n. from the Middle to Upper Devonian boundary beds of the Holy Cross Mts, Central Poland, is described and analyzed from ecologic and stratigraphic viewpoint. This new, large-beaked and small-sized species belongs 10 pedunculate forms adopted to regimes of higher, at least periodically, hydrodynamic activity which strongly influenced the brachiopod association of the stromatoporoid shoal. The species has acquired a narrow stratigraphic range and it is thus recognized as a key for the biostratigraphic division of the stromatoporoid-coraI sequence of the Holy Cross Devonian.