Lioconcha hieroglyphica
Similar to Lioconcha castrensis. Lioconcha hieroglyphica is distringuishable by its discontinuous, smaller tent markings.
Similar to Lioconcha fastigiata. Lioconcha hieroglyphica is more inflated and less elongate anterio-posteriorly than L. fastigiata.
Similar to Lioconcha ornata. Lioconcha hieroglyphica is distinguishable by its rounder shape and more inflated valves, as well as its smaller tent marks on the exterior of the flank.
Similar to Lioconcha trimaculata. Lioconcha hieroglyphica can be distinguished by its more inflated umbones.
The overall shape is trigonal ovate. The anterior and ventral margins are rounded, and the posterior margin is subtruncated. The anterior dorsal margin is nearly straight, and the posterior dorsal margin is slightly convex. The valves are equal in size and shape (equivalve), and there is no gape when they are closed. Sculpture consists of growth lines and very fine comarginal ribs ventrally, anteriorly and posteriorly. The lunule is defined by a fine shallow groove, and extends half the anterior dorsal margin. The commissural margin is slightly raised at the center of the lunule, projecting slightly above the flank of the shell. The umbones are prominent and project dorsally. The umbo is slightly anterior, and the beaks also point slightly to the anterior. The escutcheon may be lightly impressed near the umbo, but is otherwise not well defined.
The exterior is white or light tan with small light brown tent markings that are hieroglyphic-like. The pattern is distributed over the entire flank, but the markings may be slightly larger in the central area. The interior is white.
The ligament is external, extends 1/3 of the posterior dorsal margin and is supported by nymphal ridges. On the left valve, there are three cardinal teeth: the anterior (2a) and posterior (4b) teeth are not bifid, and the central tooth (2b) is robust and may be slightly bifid. The posterior tooth (4b) is fused with the nymph. There is also one anterior lateral tooth (A2) on the left valve. On the right valve, there are three cardinal teeth: the anterior (3a) and central (1) teeth are not bifid, and the posterior tooth (3b) is robust and lightly bifid. There are also two anterior lateral teeth (A1, A3) on the right valve. A fine ridge runs parallel to the posterior dorsal margin on both valves. The anterior and posterior adductor muscle scars are similar in area, but the posterior is slightly more rounded. The pallial sinus is absent or very shallow.