A new species of sciaenid, Seriphus lavenbergi sp. nov., is described from the late Miocene Yorba Member of the Puente Formation, southern California. The holotype is represented by an incomplete disarticulated skull with the right saccular (sagitta) otolith in situ, an extremely rare occurrence. This is the earliest known geological occurrence of Seriphus and represents a second species within the genus. It is hypothesized that the ancestor of Seriphus emigrated from the Gulf Stream of the Atlantic into the Pacific via the Panama Seaway and the genus evolved entirely in the eastern Pacific.