Paranomotodon angustidens (REUSS 1845) is the single described member of this genus that had worldwide distribution during the Upper Cretaceous. Known only from its relatively small teeth (to <2 cm in height) which according to Cappetta & Case (1975) are very similar to those of the extant threshers. Characteristic Paranomotodon features include:

  • smooth crown with a complete cutting and lacking cusplets,
  • medium-broad neck,
  • labial crown overhang of root,
  • labio-lingually thick root with a distinct nutrient groove and
  • wide & relatively deep, smoothly contoured basal root margin.
    On the basis of tooth-design, Paranomotodon compares well with Recent alopiids. There is not full consensus on this point (see below) and Cappetta (1987: 106) notes, "This assignment, however, remains hypothetical, because of possible convergence."

    Three topics concerning these teeth remain unresolved:

  • Anomotodon vs Paranomotodon. These two genera had very similar tooth-designs, most commonly differentiated on the basis of a striated (former) or smooth (latter) lingual crown face. There is also the matter that Paranomotodon is limited to the Cretaceous while Anomotodon is largely known from the Paleogene. Because A. novus (WINKLER 1874) teeth from Virginia usually have smooth crowns and A. plicatus ARAMBOURG 1952 is reported from the Late Cretaceous, there is the possibility that both should be included in the same family (as suggested by Herman (1979) or genus Meyer (1974).
  • Which Family? Although most authors attribute to , few, including Cappetta, do not appear particularly certain. This brightest red flag is raised by lateral cusplets (primitive characteristic) which are present in Cenozoic teeth attributed to the alopiids.
  • One or more species. Angustidens appears to be a paleo-bucket for this Cretaceous tooth-design. The European examples consistently have narrow cusps (clutching skewed) while North American teeth have broad cusps (cutting skewed). With all the splitting that goes on, it is curious that the NA design hasn't been ascribed to at least a distinct sub-species.

    Published History

    There are many reports of this taxon (some more relevant than others) many of which this author doesn't have access to the literature. These will include a reference to the particular paper in which they were found. They include:

  • Reuss (1845). Author describes (from the Turonian, Upper Cretaceous Czechoslovakia) Oxyrhina angustidens, O. acuminata, and O. heteromorpha (); angustidens has priority [Herman 1977]. Need images
  • Reuss (1846). Scoliodon priscus described in this paper [Herman 1977].
  • Fischer (1856?:142) reports Oxyrhina angustidens and O. heteromorpha [Herman 1977]. It is not known who first synonymized Reuss' taxa, but the other three generally disappear from the published record.
  • Over the next 100+ years, O. angustidens is reported by: Dalinkevicius (1935; Cenomano-Turonian of Lithuania), Leriche (1902, 1906, 1929; Turonian-Campanian France & Belgium), Taverne (1970; Upr Cretaceous of Zaire) and Woodward (1889 & 1894, 1911; Cenomano-Turonian of England), One paper (Yabe & Obata, 1930; Cretaceous of Japan) included the tooth design as Isurus angustidens [Herman 1977, Cappetta 1987].
  • Arambourg (1952: pl IV) illustrated similarly-designed (narrow-form) but striated teeth from Morocco as Anomotodon plicatus.
  • Case (1973: 20, fig 67) included the broad-form tooth-design from the Maastrichtian of NJ as Anomotodon plicatus.
  • Meyer (1974). In his unpublished thesis, the author included Anomotodon sp aff A. angustidens from Santonian-Campanian sediments of southern North America.
  • Herman (1974). In his then unpublished thesis, the author proposed the genus Paranomotodon (as an ) for these teeth previously attributed to Oxyrhina.
  • Herman (in Cappetta & Case 1975a: 24). Herman's proposed named was acknowledged in this paper with the comment that it had long been ascribed to Isurus; based on the nutrient groove it should be deemed an .
  • Herman 1977: 189-191, Pl 7 fig 7 When his manuscript was finally published, this tooth-design was included as Paranomotodon nov. gen.
  • Herman (1979) created the family for the genera Anomotodon ARAMBOURG 1952 and Paranomotodon HERMAN "1974". He wrote he was wrong (in 1974) in attributing those primitive forms to the . Herman acknowledged the similarities with but added that this is due to parallel evolution...and that the ancestors of Alopias (appearing in Palaeocene) are clearly different from the (basal folds and cusplets on lateral teeth).
  • Lauginiger & Hartstein (1983: 31-32) included the broad-form teeth from the Marshalltown Fm. (Late Campanian) of Delaware as Paranomotodon angustidens.
  • Wolberg (1985) reported this tooth-design from the Middle Turonian of New Mexico. [Shimada 1996]
  • Cappetta (1987: 106). Noted as 'pers. obs.' Paranomotodon sp specimens from the Campanian of Morocco.
  • Siverson (1992: 546). This author included this tooth-design as Paranomotodon sp (). He noted the anterior crowns were narrower then depicted in Cappetta & Case (1975) and that the type specimen was too poor to tell if it's a narrow form; so until better type locale material is found, it can't firmly attribute to specific name.
  • Manning & Dockery (1992: 26). From the Campanian of Mississippi, these authors attributed this tooth-design to Anomotodon angustidens (possibly ).
  • Welton & Farish (1993:114) included as Paranomotodon sp (?) teeth from the Santonian-Campanian of TX
  • Kent (1994: 71-72) included Paranomotodon angustidens as allied with the alopiids, from the Merchantville, Marshalltown and Severn Formations of Maryland
  • Shimada (1996: 9-10) reported Paranomotodon sp; (as an alopiid) from the Ft Hays Ls, Niobrara Fm.(?Turonian?-Middle Coniacian) of Kansas.
  • Siversson (1996: 834-35) reported Paranomotodon sp; from Mid Cretaceous of Western Australia. He considered the family association as incertae sedis, noting. "a major gap in the fossil record between the youngest Paranomotodon [uppermost Campanian. NJ] and oldest Alopias [A. denticulatus CAPPETTA, 1981; Ypresian of Morocco]." He reiterated his 1992 comments on the poor type material but commented that these Cenomanian-Turonian examples were narrow-form in contrast the broader form Campanian teeth.
  • Cappetta (2006) continued to include Paranomotodon angustidens as an .

    Acknowledgements

    Pieter - literature & discussions with Herman
    Siverson for review

    Footnotes

    1.   A variety of opinions on the appropriate family & genus are discussed herein. The broad range of opinions was disconcerting and it was deemed appropriate to follow Siversson 1996.

    Selected References

    Arambourg 1952. Les Vértebrés Fossiles des Gisements de Phoshates (Maroc-Algérie-Tunisie). Notes et Mémoires du Division of Mines and Geology, French Morocco 92, 1-372.
    Cappetta, H., 1987. Handbook of Paleoichthyology. Chondrichthyes II: Mesozoic and Cenozoic Elasmobranchii. Gustav Fischer Verlag, Stuttgart and New York, 193 pages.
    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. & Case, G., 1975a. Contribution à l'étude des sélaciens du groupe Monmouth (Campanien - Maestrichtian) du New Jersey. Palaeontographica Abteilung A, 151:1-46.
    Case, G. 1973. Fossil Sharks: a pictoral review. Pioneer Litho, NY. 64 pp.
    Fischer, C., 1856a, Die Fischreste aus den Plänerschichten von Plauen, Strehlen, Weinböhla und Grossedlitz. Allg. deutsche naturhist. Zeitg., 2: 134-145, 1 pl.
    Herman, J., 1977. Les sélaciens des terrains néocrétacés et paléocènes de Belgique et des contrées limitrophes. Eléments d'une biostratigraphie intercontinentale. Mémoires pour servir à l'explication des Cartes géologiques et minières de la Belgique, 1975 (paru 1977), 15: 401 pp.
    Herman, J., 1979. Réflexions sur la systématique des Galeoidei et sur les affinités du genre Cetorhinus à l'occasion de la découverte d'éléments de la denture d'un exemplaire fossile dans les sables du Kattendijk à Kallo (Pliocène Inférieur, Belgique). Annales de la Société Géologique de Belgique, 102: 357-377.
    Kent, B., 1994. Fossil Sharks of the Chesapeake Region. Egan Rees & Boyer, Maryland. 146 pp
    Lauginiger, E. and Hartstein, E., 1983. A guide to fossil sharks, skates, and rays from the Chesapeake and Delaware canal area, Delaware. Delaware Geological Survey, Open File No. 21. 62pp, 5 plates.
    Manning, E, and Dockery III, D, 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.
    Meyer, R. L., 1974. Late Cretaceous elasmobranchs from the Mississippi and East Texas Embayments of the Gulf Coastal Plain. Unpublished PhD dissertation, Southern Methodist University, Dallas, xiv+419 p.
    Reuss, A., 1845. Die Versteinerungen der böhmischen Kreideformation. Erste Abtheilung. - IV, Stuttgart. 58 pp
    Reuss, A., 1846. Die Versteinerungen der böhmischen Kreideformation. Zweite Abtheilung - IV, Stuttgart. 148pp.
    Shimada, K., 1996. Selachians from the Fort Hays Limestone Member of the Niobrara Chalk (Upper Cretaceous), Ellis County, Kansas. Transactions of the KS Acad.of Sc. 99(1-2) pp 1-15.
    Siverson, M., 1992. Biology, Dental Morphology and Taxonomy of Lamnifrm Sharks from the Campanian of the Kristiansand Basin, Sweden. Paleontology, 35:3 pp 519-554.
    Siverson, M., 1996. Lamniform sharks of the mid-Cretaceous Alinga Formation and Beedagong Claystone, Western Australia. Palaeontology, Vol 39:4, pp 813-49. 1997. Sharks from the mid-Cretaceous Gearle Siltstone, Southern Carnarvon Basin, Western Australia. Journal of Vertebrate Paleontogy, Vol 17:3, pp 453-65.
    Welton, B. and Farish, R., 1993. The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas. Before Time, Texas. 204 pp.
    Wolberg, D., 1985a. Selachians of the Late Cretaceous (Turonian) Atarque Sandstone Member, Tres Hermanos Formation, Sevilleta Grant, Socorro County, New Mexico. New Mexico Geology 7:1-7.
    Wolberg, D., 1985b. Selachains from the Atarque Sandstone Member of the Tres Hermanos Formation, Sevilleta Grant near La Joya, Socorro County, New Mexico. NM Bur. Mines & Min. Res. Circ. 195:7-19.
    Woodward, A. 1889. Catalogue of the Fossil Fishes in the British Museum. Part 1. London: British Museum of Natural History, 1-474.
    Woodward, A., 1911. The fossil fishes of the English Chalk. Part 6 [chimaeroids, sharks and rays], pp. 185-224, pls. 39-46. The Palaeontographical Society, London.

     

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