32. Fishes of the Mio-Pliocene Ringold Formation, Washington: Pliocene Capture of the Snake River by the Columbia River

Author(s): Gerald R. Smith, Neil Morgan, Eric Gustafson



Three rich, warm-water fish faunas occur in the Pliocene section of the Ringold Formation, near the Columbia River-Snake River confluence in south-central Washington. The fish fossils are in or near the Pasco Basin, where they accompany three mammalian local faunas of Blancan land mammal age. The White Bluffs local fauna is the earliest of the three Pliocene faunas. It is known from many localities at about 182 m (600 ft) elevation in fluvial sediments in the bluffs east of the Columbia River from 9 to 29 km north of Richland, in Franklin County, Washington. The age of the White Bluffs fauna is estimated to be 4.5 Ma. The White Bluffs fishes include Acipenser transmontanus (sturgeon), Esox columbianus n. sp. (muskellunge), Chasmistes cf. batrachops (lake sucker), Ameiurus reticulatus n. sp. (bullhead catfish), and Archoplites molarus n. sp. (sunfish). The Blufftop Locality and local fauna occurs near the northern localities of the White Bluffs local fauna in the Pasco Basin, stratigraphically higher in the Ringold Formation, at 242 m (800 ft) in elevation. Its age is middle Pliocene, about 3.7 Ma. The Blufftop fish fauna is lacustrine, and includes Acipenser transmontanus, Esox columbianus, Catostomus macrocheilus (largescale sucker), Chasmistes cf. batrachops, Ptychocheilus arciferus (northern pikeminnow), Mylocheilus heterodon n. sp. (Ringold peamouth chub), Ameiurus reticulatus, and Archoplites molarus. The Taunton Locality is between the Pasco and the Quincy Basins, in Adams County, Washington, 27 km north of the Blufftop locality. It is stratigraphically the highest of the three faunas, at 285 m (933 ft) in elevation. Its age is late Pliocene, 2.8-3.0 Ma. Fishes of the Taunton local fauna inhabited rivers and floodplains. The Taunton fish fauna includes all of the White Bluffs and Blufftop fish species, with the added presence of Klamathella milleri (Snake River chub), Acrocheiluslatus (Snake River chiselmouth chub), and Lavinia (Idadon) hibbardi (Snake River hitch).

Publication Information:

Publisher: University of Michigan

Month of Publication: December

Year of Publication: 2000

Location: Ann Arbor, MI

Volume Number: 32

# of Pages: 57