Anadara, GRAY, 1847

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 : 7

ANADARA GRAY, 1847

Neogene West American Anadara are differentiated based on the shape of the shell and the number of radial ribs, which sometimes show a medial sulcation. The best preserved Caldecott Tunnel specimens have around 31 radial ribs that are mostly not medially sulcate, although a few ribs appear to be slightly sulcate. This matches best with An. osmonti ( Dall, 1909) ( Fig. 10 ), which according to Reinhart (1943) has between 28 and 31 radial ribs that appear to not be bifurcated but on well preserved portions of shell are shown to be weakly bifurcated. Therefore, the Tsm Caldecott Tunnel fauna specimens are provisionally referred to this species. Anadara osmonti , according to Moore (1983), occurs possibly from Alaska to southern California and from formations that appear to be restricted to the middle Miocene.

Figures

Figure 10. Valves of Anadara cf. An. osmonti from the Tsm Caldecott Tunnel fauna. Hypotype from UCMP locality IP13003, UCMP 412699.