Fossils found during Bobby Boessenecker's field research. A) A nearly complete skull and lower jaw (from different individuals) of a bizarre new genus of phocoenid porpoise (also known from the San Diego Formation). B) A medium sized tympanic bulla of a minke whale-like mysticete (Balaenopteridae). C) A vertebra of a large bony fish, similar to a flounder. D) A fragment of calcified cartilage, with a magnified view showing the prismatic cartilage structure. E) Teeth of the great white shark, Carcharodon carcharias. F) The humerus (upper arm bone) of the extinct flightless penguin-like auk, Mancalla diegensis.