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

Abstract

Among the numerous and diversiform Late Cretaceoussiliceousspongescollected throughout the Volgaregion,severalrepresentatives 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.