the Volga Region

Representatives of the genus Botryosella Schrammen, 1912 (Porifera, Hexactinellida) from the Upper Cretaceous of the Volga region

Authors: Pervushov E. M.

Among the numerous and diversiform Late Cretaceous siliceous sponges collected throughout the Volga region, several representatives of the genus Botryosella have been encountered, previously unknown for the area. Analysis of the skeleton morphology, peculiar for massive transverse outgrowths, confirms manifestations of isomorphism in Hexactinellids and the opinion of inaccuracies available in the descriptive terminology applied to the skeletal morphology of this Porifera group.

Faunal Assemblage of the Maastrichtian – Paleocene Intervals of Volsk Depression

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Musatov V. A., Ermokhina L. I., Ilinskiy E. I., Lopyrev V. A., Romanov N. S., Khudyakov D. V., Voronkov I. R.

Terminal layers of carbonate rocks of Maastrichtian and lower intervals of Paleocene aleurite-pelitic formations are accessible for investigation in Krasny Oktyabr and Bolshevik quarries (Volsk Depression). In the bottom of the Paleocene accumulation of skeletons of calcareous and siliceous sponges has been confirmed, mollusk and elasmobranch assemblage has been determined. Biozonal stratification of the location section and oryctocomplex analysis have contributed to specification of the processes in succession of benthic forms at the Upper Cretaceous – Paleogene boundary.