Non-calcified macroalgae from the lower Famennian (Upper Devonian) of the Holy Cross Mountains, Poland

Non-calcified algal remains were collected from the lower Famennian deposits at the Kowala quarry in the Holy Cross Mountains, central Poland. Each specimen is represented solely by vegetative organs. On the basis of the material collected, a new algal genus and species has been formally erected. Vittella dixii nov. gen., nov. sp. (Order ?Bryopsidales) includes thalli consisting of long bundles of hair-like filament structures arranged in parallel fashion to the thallus length. Some other algal remains are regarded as Inocaulis-like forms. They possess long, flat blades with entire margins, and are ornamented with very dense, hair-like projections. The rest of the specimens found so far has been illustrated and tentatively classified as probably belonging to either Bryopsidales or Dasycladales algae. The exceptional preservation of the non-calcified algal thalli investigated suggests that special taphonomic conditions have prevailed during sedimentation of the lower part of the Famennian Kowala section. These may have involved rather rapid burial in oxygen-restricted (dysoxic and anoxic) sea-bottom environment, inhibiting the activities of scavengers and bioturbators, as well as oxidative degradation. The preservation of the algae, together with sedimentological and geochemical characteristics of the host rocks indicate that they rather represent parautochthonous assemblage, buried close to their natural habitat.