PALEOBIOGEOGRAPHY OF THE FOSSIL DECAPOD CRUSTACEANS OF THE NORTHEASTERN PACIFIC OCEAN: EXPANDING THE FOSSIL RECORD OF THE GENUS RANINA

Newly collected specimens of the fossil decapod crustacean Ranina will more than double the known fossil record of this genus from the northeastern Pacific Ocean. These include new species from the: late Eocene Hesquiat Formation of British Columbia, Canada; the late Eocene Hoko River Formation, the late Eocene to early Miocene Lincoln Creek Formation, and the late Eocene Quimper Formation of Washington; the middle Eocene Coaledo Formation of Oregon; and the Miocene Tuxpan Formation of México. This adds six new species of the genus Ranina to the three fossil species described thus far: Ranina americana from the early Miocene Clallam Formation and the Hoko River Formation of Washington; Ranina berglundi from the early Eocene Bateque Formation of Baja California, México; and Ranina tejoniana from the middle Eocene of California. These fossil occurrences demonstrate Ranina was well established in the northeastern Pacific Ocean from at least the early Eocene until the Miocene. Today the genus has only one species, Ranina ranina limited to the Indo-Pacific Ocean. Continued taxonomic work on the decapod crustaceans of the northeastern Pacific Ocean has shown an increasing correlation between genera from México to Vancouver Island, British Columbia. This is exemplified in the fossil record of the decapod crustacean genus Ranina but also reflects many other genera of decapod crustaceans, including: Archeopus, Costacopluma, Eriosachila, Eucorystes, Laeviranina, Lophoranina, Megokkos, Minohellanus, Montezumella, Portunites, Pulalius, and Zanthopsis.