Mesogastropoda

Mesogastropoda is a taxonomic group within the subclass Caenogastropoda, which itself is part of the larger class Gastropoda. Gastropods are a diverse group of mollusks that include snails, slugs, and their relatives. The Mesogastropoda were historically a large and heterogeneous order, encompassing a wide variety of marine and freshwater snails. However, modern phylogenetic studies, based on molecular data, have led to significant revisions of this classification.

The term Mesogastropoda is now considered largely obsolete in formal taxonomic systems. While it was once a widely used classification, many of the families and genera previously assigned to Mesogastropoda have been reallocated to other groups within the Caenogastropoda. These groups are now defined by more precise evolutionary relationships rather than solely on morphological characteristics.

Historically, the Mesogastropoda were characterized by a number of features, including a radula with a specific tooth structure and generally well-developed sensory organs. They included a vast array of species with diverse shell forms and ecological roles, from predatory sea snails to herbivorous freshwater species. Despite its decline in formal usage, the term "Mesogastropoda" may still be encountered in older literature or as a convenient informal grouping for certain types of snails. The current understanding of gastropod evolution relies on more refined classifications that reflect their evolutionary history more accurately.