Durham (1940) reported E. californica, and E. micropora from the Pleistocene of the Gulf of California. (Coppard & Lessios, 2017)
Coppard, S.E. & Lessios, H.A. (2017). Phylogeography of the sand dollar genus Encope: implications regarding the Central American Isthmus and rates of molecular evolution. <em>Scientific Reports.</em> 7(1): 11520.