Kingdom Animalia (animals) Eumetazoa (metazoans) Bilateria (bilaterally symmetrical animals) Protostomia (protostomes) Lophotrochozoa Trochozoa Mollusca (clams, snails, squids, and relatives) Class Bivalvia Order Unionoida Family Unionidae Genus Toxolasma Species Toxolasma texasensis (texas lilliput)