Correlation of upper Bajocian-Bathonian zones in Siberia with the stage standard

The suggestions to transfer the Arcticoceras ishmae Zone from the middle to the lower Bathonian and the Arctocephalites arcticus Zone from the lower Bathonian to the upper Bajocian put forward by some researchers, are critically considered. These suggestions are based on paleontological records from the Sokur quarry near Saratov. Based on paleontological data from Siberia represented in a number of regional ammonite, belemnite, and retroceram zonations, we infer that the proposed zonal subdivision of the Jurassic in the Sokur quarry to be untrue and believe the revision of the correlation of the above-mentioned zones with the stage and zonal standard to be premature because of insufficient argumentation.     

Propeamussiidae,Inoceramidae, and other Bivalvia from the Lower Cretaceous Puez Formation (Valanginian–Cenomanian; Dolomites,South Tyrol,Italy)

A bivalve assemblage from the Lower Cretaceous Puez Formation at the type locality, Piz de Puez (Dolomites, South Tyrol, northern Italy) is described. Given the large amount of sedimentary rock screened during the course of this study, the <50 bivalves examined here, although occurring in very low abundance, are considered to represent a reasonably comprehensive sample. The assemblage provides insight into an autochthonous, Mesozoic, deep-water bivalve community, which was dominated by glass scallops. Two species are described as new, Parvamussium pizpuezense n. sp. and the giant P. mordsdrum n. sp. Presumably, they lived as epifaunal-reclining carnivores and preyed on various meiofauna, occupying a similar ecologic niche as their modern counterparts. Scarce epifaunal, suspension-feeding Inoceramidae entered only by occasional recruitment of larvae into an environment that is inferred to have been characterised by low levels of suspended nutrients.     

Inoceramid bivalves from the Turonian/Coniacian (Cretaceous) boundary in Romania: revisions of Simonescu's (1899) material from Ürmös (Ormenis), Transylvania

Simionescu's (1899) inoceramid material from the topmost Turonian/Lower Coniacian of Ürmös (Ormenis), Transylvania, Romania contains ten species which are for the first time photographically illustrated. Of four new forms described by Simionescu (1899a), three referred here toMytiloides carpathicus(Simionescu),Cremnoceramus globosus(Simionescu), andC. transilvanicus(Simionescu), represent valid species. The type of the fourth species,Inoceramus kilianiSimionesu, represents a deformed specimen of an undetermined Late Turonian mytiloid, while the name is formally a junior synonym ofVolviceramus involutus(J. de C. Sowerby). The assemblage is time equivalent of the inoceramid association described from the Krebitz-Zittauer (Saxony, Germany) Cretaceous by Andert (1911) but, contrary to suggestions of Heinz (1930), the forms described by Andert and Simionescu are not conspecific.