Heteroconchia

Heteroconchia is a genus of fossil bivalve mollusks. These extinct marine invertebrates are known from the Mesozoic Era, primarily the Jurassic and Cretaceous periods. The shells of Heteroconchia are characterized by their inequivalve nature, meaning the two valves are of unequal size or shape. They typically exhibit a subequivalve to inequivalve morphology, with one valve often being flatter than the other. The external sculpture can vary, often featuring radial ribs, concentric growth lines, or a combination of both. The internal shell structure and muscle scar patterns are important features used in classification and understanding their paleoecology. Fossils of Heteroconchia are found in marine sedimentary rocks across various continents. Their presence indicates a shallow to moderate marine environment. The genus is part of the larger order Venerida, a diverse group of bivalves. Studying Heteroconchia provides insights into the evolution of bivalves and the paleoenvironments of the Mesozoic seas.