CHONDRICHTHYES HUXLEY, 1880

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 : 18

CHONDRICHTHYES HUXLEY, 1880

CARCHARINIFORMES COMPAGNO, 1973 CARCHARHINIFORMES INDET.

Two small (1–2 mm) fragments of a shark tooth (UCMP 270010) nonetheless preserve portions of a serrated crown. The serrations are very fine, symmetrical, and numerous with 6–7 per millimeter.

It is difficult to identify these fragments, but several shark groups have serrations of similar size and density, including members of the carcharhinids and the Lamniformes . The fine and dense nature of the serrations are more similar to the genus Carcharhinus than the larger serrations of Carcharocles , but the incomplete fossil does not permit identification beyond Order.