VESICOMYIDAE DALL AND STIMPSON, 1901

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 : 11

VESICOMYIDAE DALL AND STIMPSON, 1901

FIGS. 17–19

Three incomplete, poorly preserved specimens are assigned to Vesicomyidae , genus and species indeterminate based on their shell outline and placement of the hinge towards the anterior end of the shell. Overall they are similar in outline to Pliocardia . Pliocardia is represented by two modern species in the northern eastern Pacific, one provisionally, “ Pl.” stearnsii ( Dall, 1895) and “ Pl.” krylovata Martin and Goffredi, 2011 from Costa Rica. W.H. Dall (1896, p. 17) cites W.H. Dall (1895, p. 693) as geologic unit Cy. monilicosta was described from, it was most likely the Santa Barbara Formation where it occurs abundantly. Given this there is no data supporting a Miocene age for Cy. monilicosta , which is abundant in other Pliocene and Pleistocene formations in California (Moore 1992).

The other reported California Miocene Cyclocardia , Cy. californica has been reported from the late Miocene to Pleistocene of central and southern California (Moore 1992). In the Pacific northwest (Oregon and Washington) Cy. hannibali ( Clark, 1925) and Cy. subtenta ( Conrad, 1849) have been reported from the Miocene ( Addicott 1976, Moore 1976). Also, Allison and Marincovich (1981) provisionally (cf.) reported five western Pacific Cyclocardia from the late Oligocene to early Miocene Narrow Cape Formation on Sitkinak Island, Alaska. Unfortunately, the Caldecott Tunnel specimen is not well enough preserved for a detailed comparison with any of the Miocene western North American Cyclocardia .

Figures

Figure 17. Vesicomyidae indeterminate from the Tsm Caldecott Tunnel fauna, right valve. Hypotype from UCMP locality IP16025, UCMP 123686.

Figure 18. Vesicomyidae indeterminate from the Tsm Caldecott Tunnel fauna, right valve. Hypotype from UCMP locality IP16027, UCMP 123690.