Trophosycon, COOPER, 1894

Charles L. Powell, Ii, Clites, Erica C. & Poust, Ashley W., 2019, Miocene marine macropaleontology of the fourth bore Caldecott Tunnel excavation, Berkeley Hills, Oakland, California, USA, PaleoBios 36, pp. 1-34 : 14

TROPHOSYCON COOPER, 1894

FIG. 26

According to occurrences cited in Grant and Gale (1931) and Addicott (1970), the extinct western United States genus/subgenus Trophoscyon is possibly found in rocks of the Temblor Formation, but occurs definitively in the Santa Margarita Sands, and the lower part of the San Diego Formation. These formations indicate a possibly middle Miocene, but definitely upper Miocene to middle Pliocene age. A large number of species have been recorded for this subgenus however Addicott (1970) synonymized many of them. The single fragment from the Caldecott Tunnel excavation shows the nodes and cancellate sculpture characteristic of the taxon, but the fragmentary nature of the specimen does not allow for a more detailed identification.

Figures

Figure 26. Trophoscyon sp. Adapature view of part of the body whorl and a small portion of the penultimate whorl. Hypotype from UCMP locality IP13004, UCMP 411945.