Lazar I., Panaiotu C.E., Grigore D., Sandy M.R., Peckmann J. (2011) An unusual brachiopod assemblage in a Late Jurassic (Kimmeridgian) stromatactis mud-mound of the Eastern Carpathians (Ha˘ghimas¸ Mountains), Romania // Facies, DOI 10.1007/s10347-010-0261-x
An unusual fossil assemblage dominated by superabundant rhynchonellid brachiopods in a stromatactis mud-mound is recorded from the Ha˘ghimas¸ Mountains (Eastern Carpathians), Romania. The mound mainly consists of bioclastic wackestones to packstones with a very rich macrofauna including crinoids, sponges, juvenile ammonites, and echinoids. The brachiopods represent a low-diversity but high-abundance association, dominated by the rhynchonellids Lacunosella and Septaliphoria. The taphonomical features of the fossil assemblage indicate an autochthonous fauna, with successive generations of brachiopods in life position and complete well-preserved individuals in different growth stage alongside an accessory population of crinoids and sponges. Brachiopodbrachiopod endosymbiotic life strategy is documented for the ﬁrst time from a post-Paleozoic brachiopod assemblage. The mound reveals abundant stromatactis, ﬁlled by radiaxial ﬁbrous or drusy calcite cement and internal polymud sediments. This is the ﬁrst Late Jurassic (Kimmeridgian) stromatactis mud-mound identiﬁed in the Eastern Carpathians.