Solenidae Lamarck, 1809

Giacomino, Sebastián & Signorelli, Javier H., 2021, Systematic redescription of Solen (Ensisolen) tehuelchus and Ensis macha (Bivalvia: Solenoidea) from Argentina, southwestern Atlantic Ocean, Zootaxa 4964 (3), pp. 541-558 : 542-544

Family Solenidae Lamarck, 1809

Diagnosis: Medium to large cylindrical shell, laterally compressed and gaping at both ends, anteriorly end very short with a sub-terminal anterior umbo. Hinge plate with two cardinal teeth, one in each valve and no lateral teeth; pallial sinus shallow, adductor muscle scars different in size and shape, the anterior muscle elongated, teardrop-like; the posterior smaller, sub-circular to oval; external and long ligament, postero-dorsally positioned ( Coan et al. 2000; Cosel 1990; Huber 2010).

Comparison: In contrast to Solenidae , the family Pharidae is characterized by a medium to large elongate shell, thin, fragile, with anterior and posterior ends rounded, laterally compressed, umbo subterminal ( Siliqua , Cultellus ) to terminal ( Ensis ), external surface smooth with concentric and irregular growth lines, ligament external and opisthodetic, hinge plate with 1 to 4 cardinal teeth in the left valve, shell ultrastructure with three layers, the prismatic outer, the crossed lamellar medium and the complex cross lamellar inner layers ( Cosel 1990, 1993, 2009).