Originoida

Originoida is a taxonomic order within the class Bivalvia, encompassing a diverse group of saltwater clams. These bivalves are characterized by their relatively equivalve shells, meaning both shells are generally equal in size and shape, though variations can occur. The hinge ligament is typically opisthodetic, meaning it is located behind the hinge itself. Many species within Originoida are infaunal, meaning they live buried within the seafloor sediments, ranging from mud and sand to gravel. They achieve this by using a strong, muscular foot to burrow.

The feeding strategy of Originoida members is primarily filter-feeding. They use their siphons to draw in water, filtering out small particles of organic matter and plankton from the water column for sustenance. The size of originoid clams can vary significantly, from small species measuring only a few millimeters to larger ones that can exceed several centimeters in length. Their geographical distribution is widespread, found in marine environments across the globe, from temperate to tropical waters. Some well-known families within this order include the Tellinidae (tellins) and the Solenidae (razor clams), each with distinct shell morphologies and ecological roles. The study of Originoida contributes to our understanding of marine biodiversity, sediment dynamics, and the trophic interactions within coastal ecosystems.