CODAKIINAE KOROBOKOV, 1954

Charles L. Powell, Ii, Clites, Erica C. & Poust, Ashley W., 2022, Miocene marine macropaleontology of the fourth bore Caldecott Tunnel excavation, Berkeley Hills, Oakland, California, USA, PaleoBios 36, pp. 1-34 : 22

CODAKIINAE KOROBOKOV, 1954

FIG. 38

UCMP 218710, a single right valve in sandstone, is provisionally identified as Lucinoma cf. L. annulatum (Reeve 1850) based on its shape, sculpture and possibly late Miocene age. Lucinoma annulatum occurs from the late Miocene to Holocene of the eastern Pacific but has been reported from the Oligocene in Japan and Russia (Okamoto and Sakai 1995, Kafanov and Ogasawara 2004), however these older ages seem doubtful. No other fossil Lucinoma species are known from the late Miocene of California.However L. annulatum is very similar to and can be difficult to separate from Lu. acutilineata ( Conrad, 1849) . Lucinoma acutilineata occurs in Oligocene to middle Miocene (Roth 1979, Moore 1988) rocks from Alaska south to southern California (Moore 1988) and L. hannibali Clark, 1925 from the Oligocene to middle Miocene of the Pacific Northwest. Lucinoma acutilineata is distinguished by its lighter hinge, and longer posterior dorsal margin (Stewart in Tegland 1933, p. 116), while L. hannibali is distinguished by its longer and wider lunule, having a longer and more concave dorsal margin, a more subdued sulcus running from near the umbo to posterior margin, and sometimes more irregularly spaced comarginal sculpture. The possibly early Oligocene to ( Collins and Rudkin 1981) and they are widespread in marine and marginal marine environments.

Figures

Figure 38. Lucinoma cf. L. annulatum. Claremont Caldecott Tunnel fauna, right valve(?). Hypotype from UCMP locality IP13007, UCMP 218710.