The genus Lonchidion was erected by Estes (1964) based on isolated teeth from the Maastrichtian of Wyoming. Duffin (1985) synonymized Lonchidion with Lissodus BROUGH 1935; Antunes et al. (1990) suggested two or more taxa might be present in the consolidated "Lissodus". Rees & Underwood (2002) sorted Duffin's "Lissodus" bucket into five genera: Lissodus, Lonchidion, Parvodus gen. nov, Steinbachodus REIF 1980 and Vectiselachos gen. nov. (plus some uncertain tooth-designs) based on tooth and dentition-design.1

The Rees & Underwood (R&U2002) Lonchidion species list is North America-centric with taxa also reported from the eastern Atlantic:

  • Lonchidion anitae THURMOND, 1971 - ?Aptian-Albian (L. Cret) of Texas, USA;
  • L. babulskii CAPPETTA AND CASE, (1975a: 7 pl 1 fig 7-12) -- Campanian (L. Cret) of New Jersey; R&U2002 note: "teeth of L. babulskii are rarely well preserved but the thin teeth and the shape of the labial protuberance support its inclusion in Lonchidion".
  • L. breve PATTERSON, 1966 -- Valanginian-Barremian (E. Cret) of England (morphology very similar to that of L. selachos).
  • L. crenulatum (PATTERSON, 1966) -- Berriasian-Valanginian (E. Cret) of England;
  • L. delsatei (GUENNEGUES AND BIDDLE, 1989) -- Toarcian (Jurassic) of France: known only from two poorly preserved teeth.
  • L. griffisi (CASE, 1987) -- Campanian (L. Cret.) of Wyoming;
  • L. humblei MURRY, 1981 -- Carnian (Upper Triassic ) of Texas;
  • L. inflexum UNDERWOOD AND REES, in press -- Berriasian (E. Cret) of England;
  • L. marocensis (DUFFIN AND SIGOGNEAU-RUSSELL, 1993) -- ?Berriasian (E. Cret) of Morocco;
  • L. microselachos ESTES AND SANCHÍZ, 1982 -- Barremian-Aptian (E.-L. Cret) of Spain; morphology very similar to that of L. selachos.
  • L. selachos ESTES, 1964 -- Maastrichtian (L. Cret.) of Wyoming.;
  • L. striatum PATTERSON, 1966 -- ?Hauterivian-Barremian (E. Cret) of England;
  • L. weltoni (DUFFIN, 1985) -- Cenomanian (L. Cret) of Oregon.
  • Unnamed Lissodus species (Cenomanian-Maastrichtian) figured by Welton and Farish (1993: 55) and one by Cappetta and Case (1999:9, pl 1.8, Late Cenomanian); these may be synonymous and appear to be Lonchidion.
  • Lonchidion teeth from the Muschelkalk (Ladinian?) of Crailsheim in Germany (Patterson, 1966: 331).
  • Unnamed teeth from the Carnian of Virginia, US (Johansson, 1992), have a morphology close to that of the type species of Lonchidion.
  • Bourdon et al (2011) included as Lonchidion sp a single (?anterior) tooth (with root) from the Santonian of New Mexico.

    Referring to the Duffin's consolidated genus, Cappetta (1987: 34-36) deemed them freshwater but noted that North American species were found in marine sediments and, depending on species, the teeth would form a cutting or crushing dentition.. Maisey (1996: 106) points out that freshwater members of this genus were very small, noting that a Permian species from Africa was less than 15 cm in length. Rees & Underwood (2002) commented "through the lifetime of the genus, the sharks were more diverse in non-marine environments and it is only in the Late Cretaceous that they occur in fully marine settings."

    There are multiple reports of Lonchidion (usually as Lissodus) along the East & Gulf Coasts and Interior Sea of North America; in additions to the above references, others include:

  • Lauginger & Hartstein (1983) - L. babulskii - Late Cretaceous, Maryland
  • Georgia Case & Schwimmer (1988: 292: fig 4.9-4.12) - five L. babulskii - Campanian of Georgia.
  • Manning & Dockery (1992: 6. pl 3, fig 5) - L. babulskii - Late Cretaceous of Mississippi.
  • Welton & Farish (1993) ascribed to Texas deposits: L. anitae (Albian, pg 53), L. selachos (Campanian, pg 54) and two undescribed species (Cenomanian-Maastrichtian, pg 55).
  • Case & Cappetta (1997:134 pl 2 fig 5-6) - three L. aff babulskii - Upper Maastrichtian of Texas.
  • Cappetta & Case (1999:9, pl 1, fig 8) - single Lissodus sp - Upper Cenomanian of Texas.
  • elasmo.com (1999) deemed the Black Creek (Campanian, North Carolina) teeth to most likely represent L. babulskii.
  • Case et al (2001:87, pl 1, fig 8-11) reported L. babulskii from the Santonian of Georgia.

    It seems to be normal that isolated teeth from this genus are found without roots - this has certainly been the author's experience. The illustrated example (fig ) is from Black Creek sands and represents the best available specimen (damage/wear from feeding is usually compounded by transportational wear). The tooth is laterally elongated with a transverse ridge/cutting edge, distinct labial protuberance and low central cusp (worn in illustrated specimen). Cappetta (1987) describes the root of this genus as being flat and perpendicular to the crown's axis. It has a broad oblique lingual face and a labial with numerous foramina.

    Footnotes

    1.   Rees & Underwood (2002) note, "No skeletal remains are known of Lonchidion except for a few incomplete skeletons from the Lower Cretaceous of Spain, described as "Lissodus palustris" GOMEZ-PALLEROLA, 1992 and possibly belonging to Lonchidion."


    Selected References

    Antunes, M., J. Maisey, M. Marques, B. Schaeffer and K. Thomson. 1990. Triassic fishes from the Cassange Depression (R. P. de Angola). Ciências da Terra (UNL), Número Especial 1990:1-64.
    Bourdon, J., Wright, K., Lucas, S.G., Spielmann, J.A. and Pence, R., 2011. Selachians from the Upper Cretaceous (Santonian) Hosta Tongue of the Point Lookout Sandstone, central New Mexico. New Mex. Mus. Nat. His. and Sc., Bulletin 52; 54pp.
    Cappetta, H., 1987. Chondrichthyes II. Mesozoic and Cenozoic Elasmobranchii. In: Handbook of Paleoichthyologie, vol. 3b, Gustav Fischer Verleg, Stuttgart, 193 pp.
    Cappetta, H. and G. Case, 1975a. Contribution à l'étude des sélaciens du groupe Monmouth (Campanien - Maestrichtian) du New Jersey. Palaeontographica Abteilung A, 151:1-46.
    Cappetta, H. and G. Case, 1999. Additions aux faunes de sélaciens du Crétacé du Texas (Albien superieur-Campanien). PalaeoIchthyologica 9, München. pp 5-111.
    Case, G. and H. Cappetta., 1997. A new selachian fauna from the late Maastrichtian of Texas. Muünchener Geowissenschaften Abhandungen 34:131-189.
    Case, G and D. Schwimmer, 1998. Late Cretaceous fish from the Blufftown Formation (Campanian) in Western Georgia.Journal of Paleontology., 62(2). pp 290-301.
    Case, G, D. Schwimmer, P. Borodin and J. Leggett, 2001. A new selachian fauna from the Eutaw Formation (Upper Cretaceous/Early to Middlew Santonian) of Chattahoochee County, Georgia. Palaeontographica Abt. A, 261:83-102.
    Derycke, C., R. Cloutier, and A.-M. Candilier. 1995. Palaeozoic vertebrates of northern France and Belgium: part II - Chondrichthyes, Acanthodii, Actinopterygii (Uppermost Silurian to Carboniferous). Geobios, M.S. 19, 343-350.
    Duffin, C. J. 1985. Revision of the hybodont selachian genus Lissodus Brough (1935). Palaeontographica Abt. A 188:105-152.
    Estes, R. 1964. Fossil Vertebrates from the Late Cretaceous Lance Formation, Eastern Wyoming. University of California Publications in Geologic Sciences 49:1-187.
    Gomez-Pallerola, J. E. 1992. Nota sobre los Tiburones hybodontos de las calizas litograficas del Cretacico Inferior del Montsec (Lerida). Boletin Geologico y Minero 103:3-33.
    Maisey, J. G. 1996. Discovering Fossil Fishes. Henry Holt & Co., NY. 223 pp
    Manning, E. and D. Dockery III, 1992. A guide to the Frankstown vertebrate fossil locality (Upper Cretaceous), Prentiss County, Mississippi. Mississippi Dept. of Env. Qual., Office of Geology, Circular 4, 43 p., 12 pls.
    Rees, J. and C. Underwood, 2002. The status of the shark genus Lissodus BROUGH, 1935, and the position of nominal Lissodus species within the Hybodontoidea (Selachii) JVP 2002, 22: 471-479.
    Schwimmer, D., 1986. Late Cretaceous fossils from the Blufftown Formation (Campanian) in western Georgia. The Mosasaur, III:109-119.
    Welton, B. and R. Farish, 1993. The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas. Before Time, Texas. 204 pp.

     

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