Reported only from oral teeth, Texatrygon is an extinct sawfish-like batoid from the Late Cretaceous of North America and Morocco (Cappetta & Case 1999:42). The tooth-design placed in this genus was previously included as Ptychotrygon; however, Cappetta & Case (1999: 41) deemed that the absence of a transverse ridge on the labial crown face sufficient for erecting the new genus. Their diagnostic criteria for the genus were:

  • a labial face lacking transverse folds
  • a crown with completely smooth enamel or bearing short labial basal folds (vertical or projecting outward)
  • a cuspidate crown.
    Cappetta & Case made no mention of rostral spines.

    Species placed in this genus by Cappetta & Case (1999) included:

  • Texatrygon copei CAPPETTA & CASE 1999 [Lower Campanian, Texas]. Compared with the better known T. hooveri:
    - occlusally: the labial margin is more angular and the transverse ridge concave on each side
    - laterally: the lingual face is gently concave & labial weakly convex, the labial uvula is robust and direct downward.
    - lingually: the uvula is rather strong but the indent above it very weak.
  • Texatrygon hooveri (MCNULTY & SLAUGHTER, 1972) [Type species, Turonian, Texas]. In addition to specimens previously attributed to hooveri, they synonymized:
    - P. rubyae WILLIAMSON, KIRKLAND & LUCAS, 1993 and
    - P. greybullensis CASE 1987 Late Campanian of Wyoming.
    Other reports of T. hooveri were included in: Meyer (1974:122-23), Cappetta (1987:156-57) and Welton and Farish (1993: 147-51). The figured Coniacian examples from New Mexico (Fig. & ) compare well with Cappetta & Case (1999) description and figures.
    - Hamm & Cicimurri (2011:120) included Texatrygon hooveri in the Atco Formation (Early Coniacian) of Texas.

    In addition to those original species:

  • Texatrygon sp. The accompanying specimen (Fig. ) from the Late Cretaceous of Mississippi follows the genus description. The crown is high & cuspidate, and the labial face of the crown is smooth with no transverse trough. The thick visor also corresponds with the design of T. hooveri.
  • Texatrygon stouti BOURDON et al 2011 The below specimens (Figs. -) from the Santonian of New Mexico are similar to Texatrygon hooveri however they lack the lower labial bumps and/or ridges. In addition, these authors propose a rostral spine design that may belong with these oral teeth.

    Selected References

    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, 1999. Additions aux faunes de sélaciens du Crétacé du Texas (Albien supérieur-Campanien). Palaeoichthyologica, 9, 5-111.
    Case, G., 1987. A new selachian fauna from the Late Campanian of Wyoming (Teapot Sandstone Member, Mesaverde Formation, Big Horn Basin) Palaeontographica Abteilung A, v. 197, p. 1-37.
    Hamm, S.A. and D.J. Cicimurri, 2011. Early Coniacian (Late Cretaceous) selachian fauna from the basal Atco Formation, Lower Austin Group, north central Texas; Paludicola [Rochester Institute of Vertebrate Paleontology] 8(3):107-127.
    Kriwet, J., 2004. The systematic position of the Cretaceous sclerorhynchid sawfishes (Elasmobranchii, Pristorajea) In: Mezozoic Fishes 3 - Systematics , Palaeoenvironments and Biodiversity. Arratia & Tintori (eds.); Pfeil, Germany. pp 57-73.
    Kriwet, J., Nunn, E. and Klug, S., 2009. Neoselachians (Chondrichthyes, Elasmobranchii) from the Lower and lower Upper Cretaceous of north-eastern Spain. Zoological Journal of the Linnean Society, 2009, 155, 316-347, 12 figures
    McNulty and B. Slaughter, 1972. The Cretaceous selachian genus, Ptychotrygon JAEKEL 1894. Eclogae geol. Helv., 65(3):647-656, fig. 1-2, pl 1.
    Meyer, R., 1974. Late Cretaceous elasmobranchs from the Mississippi and East Texas embayments of the Gulf Coastal Plain. Unpubl. PhD dissertation, Southern Methodist Univ., Dallas, xiv+419 p.
    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.
    Williamson, T., J. Kirkland and S. Lucas, 1993. Selachians from the Greenhorn cyclotherm (Middle Cretaceous: Cenomanian-Turonian), Black Mesa, Arizona, and the paleogeographic distribution of late Cretaceous selachians. Journal of Paleontology 67(3): 447-474, 15 fig.

     

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