Sarmentofascis? digitatus n. sp., a new cladocoropsid stromatoporoid from the Tithonian-early Berriasian (Late Jurassic-Early Cretaceous) of the Ay-Petri massif (Crimea Peninsula)

摘要

The new stromatoporoid sponge Sarmentofascis? digitatus n. sp. (family Cladocoropsidae) is described from the Tithonian-Early Berriasian of the Crimea Peninsula. The skeleton has a digitate shape, with thin cylindrical stems, displaying characteristic subparallel (palisade-like) dichotomous branching. The internal structure of the mostly strongly recrystallized specimens is reticulate without any tube differentiation (e.g., astrorhizal canals). With the digitate and biostromal development, the skeletons of S.? digitatus acted as sediment-bafflers. The three-dimensional structures are associated with microencrusters (foraminiferans, thaumatoporellaceans) that occupy the spaces between the stem-like cylindrical forms. The skeletons accumulated to form Sarmentofascis-bearing biostromes that may be interpreted to represent a habitat in the outer lagoonal zone behind marginal reef flats.