Scindocorax Bourdon et al (2011:11-15, figs. 7-9) is a small anacoracid shark reported only from the E-M Santonian of New Mexico. The singular known locale is thought to represent a near shore marine setting with riverine elements. The narrow cusps of Scindocorax suggest a tearing functionality.

In Scindocorax novimexicanus BOURDON et al, 2011 (Figs. - below), the teeth are small (~5 mm class), the crowns have a smooth subtriangular cusp with serrations that extend 80-90% up the cusp; serrations are usually small and homogeneous but mesial ones may be inflated. Lingually, the neck is broad and the root may bear foramina; labially, the basal crown face extends beyond the root with a series of foramina below.
In anterior teeth the cusp is narrow; becoming more inclined with a better-developed heel distally. The root is high, labiolingually thick and mesiodistally compressed; the lobes are long, rather erect, and poorly splayed. The mesial lobe tends to be longer and the distal more erect.
In lateral teeth, the cusps are broader and more inclined; the heel well developed; the root is lower, more labiolingually compressed, and the lobes more splayed.

Bourdon et al (2011:15, figs. 9) included a second-tooth design as Scindocorax sp. aff. S. novimexicanus (Figs. - below). It was generally similar to the former, but differed in:

  • Robustness: S. novimexicanus is more gracile and S. sp. aff. S. novimexicanus stouter;
  • Crown wear: In the gracile form, apical serrations tend to be worn while in the stouter teeth there is greater crown damage (?feeding strategies);
  • Root durability: Short ultrasonic cleaning tended to fragment or disintegrate the gracile form while the stouter form resisted longer session with no damage;
  • Foramina placement: When visible, the labial foramina were positioned lower on the stout form;
  • Relative abundance: The gracile is four-times as common as the stout form.
    The author's concluded that (seasonal) gynandric heterodonty could account for these variations.

    For the dentition they concluded:

  • disjunct monognathic heterodonty;
  • weak to moderate dignathic heterodonty.
  • gynandric heterodonty (or a second species);
  • little or no ontogenetic heterodonty;
  • tooth count likely about 12-files per quadrant;
  • tearing functionality.


    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.

     

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