This genus is known from Europe, Asia and North America deposits, but only from isolated teeth. Some of the relevant published reports for the NA fauna include:

  • Cope (1875: 297) described Lamna macrorhiza for teeth from the Albian of Texas.
  • Cappetta (1975c) reported Odontaspis macrorhiza for teeth from the Aptian of France.
  • Cappetta & Case (1975a: 23-24, pl 3,1-9) described Plicatolamna borodini for teeth from the Mt. Laurel Fm. (Late Campanian) of New Jersey.
  • Cappetta (1980c) erected the genus Protolamna and attributed to it his Odontaspis macrorhiza specimens under the name Protolamna sokolovi.
  • Launginiger & Hartstein (1983: 28-29, pl 3.32-33) reported Plicatolamna borodini from the Marshalltown Fm. of Delaware.
  • Cappetta (1987:98) accepted Cretodus as a valid genus and included borodini as such.
  • Case & Schwimmer (1988: 295, figs 5.13-15) reported Cretodus borodini from the Campanian of Alabama and Georgia.
  • Welton & Farish (1993: 110-11) included from Texas: Protolamna aff sokolovi (Albian-Cenomanian) and included an artificial tooth-set (Albian). They went on to note that the Protolamna tooth-design had been found as high as the Kemp Clay (Maastrichtian).
  • Cappetta & Case (1999:25-26) reported three species from Texas:
      - Protolamna compressidens (HERMAN 1997) (pl. 12.1-2; Turonian-Coniacian)
      - P. carteri nov. sp. (pl. 12.3-5; Upper Cenomanian) and
      - P. roanokeensis nov. sp. (txt fig 8; Albian); to which they synonymized Cope's macrorhiza and Welton & Farish's aff sokolovi.
  • Case et al (2001:91-92, pl 3, fig 59-64) reported Cretodus borodini from the Santonian of Georgia.
  • Case & Cappetta (2004:11) reassign Cretodus borodini to Protolamna.
  • Cappetta (2006) included borodini in Protolamna.
  • Kriwet et al (2008) erect and include Eoptolamna and Protolamna in this new family.
  • (2008) included borodini as present in the Late Campanian of Mississippi.
  • Hamm & Cicimurri (2011:114) included P. compressidens in the Atco Formation (Early Coniacian) of Texas.

    The cusp is relatively short & erect, triangular & elongated but never particularly broad; the labial face is flat with folds and overhangs the root; the lingual is highly convex, usually with folds and a distinct neck. The cutting edge is complete, and in most species the shoulders bear divergent triangular cusplets well separated but not detached from the main cusp. The bilobate roots have a U-shaped basal margin, long lobes and a strong lingual protuberance. Some teeth show evidence of a very weak nutrient groove. The teeth of P. borodini are small, have elongated root lobes and bear strong folds on the lingual and labial surface of most teeth.

    Selected References

    Cappetta, H., 1975c.Sélachians et Holocéphale du Gargasien de la région de Gargas (Vaucluse). Géologic Méditerraneenne, 2, 115-134
    Cappetta, H., 1980c. Modification du statut générique de quelques espèces de sélaciens crétacés et tertiaires. Paleovertebrata, 10, (1). pp 29-42.
    Cappetta, H., 1987. Chondrichthyes II. Mesozoic and Cenozoic Elasmobranchii. In: Handbook of Paleoichthyologie, vol. 3b, Gustav Fischer Verleg, Stuttgart, 193 pp.
    Cappetta, H., 2006. Elasmobranchii post-Triadici (index generum et specierum). In: Riegraf, W. (Ed) Fossilium Catalogus I:Animalia 142. Leiden, Backhuys Publish, 472pp.
    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.
    Case, G., and H. Cappetta,2004. Additions to the elasmobranch fauna from the Upper Cretaceous of New Jersey (Middle Maastrichtian, Navesink Formation). Palaeovertebrata 33.
    Case, G., and D. Schwimmer, 1988. Late Cretaceous fish from the Blufftown Formation (Campanian) in western Georgia. Journal of Paleontology 62:290-301.
    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.
    Cope, E., 1875 The Vertebrata of thé Cretaceous Formations of thé West. Report of the USGS, vol II p297 XLII figs 9,10
    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., S. Klug, J.Canudo and G. Cuenca-Bescos, (2008). A new Early Cretaceous lamniform shark: Eoptolamna eccentrolopha gen. et sp. nov. (Chondrichthyes, Neoselachii). Zoological Journal of the Linnean Society, 154: 278-290.
    Lauginiger, E., and E. Hartstein, 1983. A guide to fossil sharks, skates and rays, from the Chesapeake and Delaware Canal area, Delaware. Delaware Geological Survey Open File Report 21, 643 pp
    Schwimmer, D., G. Hooks, and B. Johnson, 2002. Revised taxonomy, age, and geographic range of the large lamniform shark Cretodus semiplicatus. Journal of Vertebrate Paleontology 22(3):704-707.
    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.