The oldest evidence of non-coaxial shell heterostrophy in the Class Gastropoda

Abstract

The term shell heterostrophy describes the condition where the shellwhorls coil in one direction during one portion of a gastropod's life,and in the other direction for another portion. In the present paper,the oldest evidence of non-coaxial shell heterostrophy in the ClassGastropoda is documented in the new species Koneprusellia zaki sp. nov.(Porcellioidea, Archaeogastropoda), coming from the Early Devonian ofthe Barrandian area (Bohemia). A brief analysis of the occurrences ofthis shell's morphological features, among the Paleozoic gastropods,revealed that the shell heterostrophy was present in at least threeunrelated gastropod lineages: in the clades Heterobranchia(Devonian-Recent), Macluritoidea (Ordovician), and Porcellioidea(Silurian-Cretaceous).