Kokuraichthys tokuriki n. gen. and sp., Early Cretaceous osteoglossomorph fish in Kyushu, Japan.

Bulletin of Kitakyushu Museum of Natural History and Human History, Ser. A 01/2013; 11:67-72.


Kokuraichthys tokuriki is described from the Early Cretaceous Dobaru Formation of the Wakino Subgroup, Kitakyushu in the northern part of Kyushu, Japan, as a new genus and species of Osteoglossomorpha. This new species is considered to be more closely related to Hiodontiformes or Lycopteriformes than Osteoglossiformes because it has a single epural and no neural spine on the first ural centrum. Although it has significantly fewer vertebrae (36 or 37), K. tokuriki is tentatively assigned to Hiodontiformes because of the long anal fin base, the anterior position of the dorsal fin and the reduced neural spine on the first preural centrum.

Download full-text


Available from: Yoshitaka Yabumoto, Oct 03, 2015
71 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: The new species Eohiodon woodruffi is the second known species of the fossil hiodontid genus Eohiodon. It occurs in Middle Eocene freshwater tuffaceous shales of the lower Tom Thumb Tuff Member and the Middle Member of the Klondike Mountain Formation, near Republic, Washington. The new species differs from Eohiodon rosei in having more anal fin rays and in being deeper bodied. Eohiodon woodruffi also occurs with Eohiodon rosei in Eocene sediments near Horsefly, British Columbia.
    Canadian Journal of Earth Sciences 05/1978; 15(5):679-686. DOI:10.1139/e78-075 · 1.58 Impact Factor
  • Journal of the Geological Society of Japan 01/1951; 57(666):95-98. DOI:10.5575/geosoc.57.95
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hiodon is a Recent genus of fishes endemic to the fresh waters of North America; it is represented by two species: Hiodon tergisus Lesueur and H. alosoides (Rafinesque). Two specimens of osteoglossomorph collected from the Eocene-Oligocene Kishenehn Formation of northwestern Montana represent a new fossil species that is more closely related to the Recent Hiodon than it is to the Eocene †Eohiodon. The close relationship of this new species to Hiodon is supported by derived characters of the nasal, the opercular series, the jaws, the basihyal tooth plate, the infraorbitals, and the caudal skeleton.Comparative study of the postcranial skeleton of Recent and fossil hiodontids illustrates several stages in the evolution of the Hiodontidae: 1) origin of seven-rayed pelvic fins by the late Early Cretaceous (evidenced by †Yanbiania); 2) development of an anal fin larger than the dorsal fin and supported by 16 or more anal pterygiophores at least as early as the early Late Cretaceous (evidenced by †Plesiolycoptera); 3) evolution of a falcate dorsal fin and a sexually dimorphic anal fin at least as early as the Eocene (evidenced by †Eohiodon); and 4) increase in number of vertebrae accompanied by changes in the caudal skeleton as seen in the new fossil species and in Recent species of Hiodon.
    Journal of Vertebrate Paleontology 06/1994; 14(2):153-167. DOI:10.1080/02724634.1994.10011549 · 1.98 Impact Factor