Notogoneus

Abstract: Background The Green River Formation (early Eocene, about 42–53 Ma) at and near Fossil Butte National Monument in Wyoming, USA, is world famous for its exquisitely preserved freshwater teleost fish in the former Fossil Lake. Nonetheless, trace fossils attributed to fish interacting with the lake bottom are apparently rare, and have not been associated directly with any fish species. Here we interpret the first known feeding and swimming trace fossil of the teleost Notogoneus osculus Cope (Teleostei: Gonorynchidae), which is also represented as a body fossil in the same stratum.

Abstract: †Notogoneus osculus Cope, the type species for the geographically widespread Upper Cretaceous to Upper Oligocene genus †Notogoneus (Gonorynchidae), is redescribed in detail based on much new material. This species is known from the Early Eocene Fossil Butte Member of the Green River Formation, southwestern Wyoming. It is geologically the youngest known species of the family Gonorynchidae in North America, although the family is known from Oligocene and Miocene lacustrine deposits of Europe and Australia and is extant today in tropical marine environments of the Pacific (Gonorynchus spp.). In this paper we also correct a number of mistakes in previously published morphological descriptions of †N. osculus (e.g., in skull and caudal skeleton) based on a large, new sample of well-preserved, well-prepared specimens. Accurate description of this species is important because it is the type for the genus and it is also by far the best preserved of all known species of †Notogoneus. In addition, it may she...

Abstract: Two specimens of fossil fish from the Eocene and Oligocene were recently discovered near Paris. Zapteryx bichuti n. sp. is from limestone of Lutetian (middle Eocene) age in the Civet-Pommier quarry near Saint-Vaast-les-Mello. Notogoneus janeti Priem is from marl of lower Oligocene age in the Lambert quarry near Cormeilles-en-Parisis.

Abstract: Early Eocene fluvial ichthyofaunas of Wyoming are relatively poorly known compared with the better-preserved lake deposits of the Green River Formation. We describe the teleost fishes from a single floodplain locality in the main body of the Wasatch Formation that immediately predates the formation of Lake Gosiute, in the Washakie Basin of Wyoming. This assemblage was deposited during the Graybullian substage of the Wasatchian Stage, corresponding to the onset of the rapid climatic warming leading to the Early Eocene Climatic Optimum. In addition to a lepisosteiform and an amiid, the locality has a teleost ichthyofauna comprising Diplomystus (Ellimmichthyiformes), a gonorynchiform probably representing Notogoneus, amblyopsid-like percopsiforms that may represent up to three taxa, and perciforms among which are probably an indeterminate centrarchid and ‘Priscacara.’ The fauna demonstrates that many of the Green River Formation fish taxa were already present in fluvial environments prior to the form...