Evolutionary, Paleoecological and Taphonomic Aspects of New Agglutinated Foraminifer Devonodendron Scopulum from the Frasnian of Holy Cross Mts, Poland

Regularly bifurcated tubiform microfossils, although illustrated three decades ago from the Frasnian of the Holy Cross Mts (southern Poland), have not been studied in detail until now. In this paper, the distinctive microproblematic is interpreted as a benthic agglutinated foraminifer belonging to Devonodendron scopulum sp. et gen. nov., appearing in a major radiation after the Givetian Revolution. The species is considered to be the oldest known representative of the family Dendrophryidae, related to the living genus Psammodendron, already reported from the fossil record (Cretaceous; questionable Silurian). The tree-like branching system of this species suggests erect attached habit. D. scopulum shows a pronounced microhabitat selectivity, being dominantly restricted to mid-slope metazoan-microbial mud-mounds. The buildups provided microniches for the flourishing of a very abundant and diverse calcareous microbiota, including taxa with known (Nanicella) and presumed (Eifeliflabellum) foraminiferal affinities. The environment was characterized by a specific diagenetic setting for the fossilization of micritic-organic tubular tests due to rapid microbially mediated lithification and overwhelming recrystallization processes. As a result, microfossils are largely preserved as stacked homogeneous rhomboidal calcite plates. Many specimens are actually just coalesced sparry calcite 'pseudomorphs' mimicking the original test morphology.