Huber (2010) considers that S. parocellatus may be an older than for S. eastae.
Huber, M. (2010). Compendium of bivalves. A full-color guide to 3,300 of the world’s marine bivalves. A status on Bivalvia after 250 years of research. Hackenheim: ConchBooks. 901 pp., 1 CD-ROM. (look up in IMIS)