Upper Cretaceous Fish Remains from the Western Border of the San Joaquin Valley, California

Abstract

The only previously recorded Cretaceous fish fossils from California are four scales described by Cockerell (1919). These represent three types, Chicolepis punctatus, Pomolobus? chicoensis, and Erythrinolepis chicoensis, from the Moreno formation on the south side of Ortigalito Creek; and one additional form, Echidnocephalus? pacificus, possibly from the Moreno between Little Panoche and Ortigalito creeks in the middle Coast Ranges. Fortunately a much more considerable amount of Cretaceous fish fossil material is available for the present report. Most of this comes from oil-well cores from the middle San Joaquin Valley. Only a limited number of localities yielded materials for study; this fact is the more unusual in that Cretaceous deposits are widespread in the state. Even so, the present collection does include many well preserved forms, some of which occur in great abundance. Fortunately the total collection gives a representative cross section of the piscine fauna and comprises such families as might be expected. A satisfactory representation of the genera likewise is found. The more important members of the Upper Cretaceous fish faunas of California appear to be found among forms from Panoche Creek, and these may well serve as a foundation for future studies of related fish types.