Iberotrygon

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Iberotrygon
Temporal range: Late Cretaceous, 95 Ma
↓
Iberotrygon holotype tooth.png
Holotype tooth (MPZ 2005-33)
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Chondrichthyes
Order:
†Sclerorhynchiformes
Genus:
†Iberotrygon

Kriwet, Nunn & Klug, 2009
Binomial name
†Iberotrygon plagiolophus
Kriwet, Nunn & Klug, 2009

Iberotrygon is an extinct genus of sclerorhynchiform ray from the Cenomanian of Spain. Only the single species I. plagiolophus, is known; it was named and described in 2009.[1] It is known from the holotype MPZ 2005-33, an antero-lateral tooth, and the parartypes MPZ 2005-34, four well-preserved teeth from a single juvenile?, and MPZ 2005-35, an isolated tooth (all found in Sample 4 from Facies 2).

The tooth crown of Iberotrygon is cuspidate, with a well-developed, high, pointed, main cusp that is inclined lingually in teeth of juveniles and adults.[1] The lingual margin of the crown overhangs the root, especially towards the apex. The crown is bulky and well defined, while the crown shoulders are short and low, while contrastingly, the cutting edge is blunt but continuous between the central cusp and crown shoulders. In occlusal view the crown is devoid of distinct transversal crests. However, there is some ornamentation, most notably a longitudinal medio-labial ridge, which sometimes bifurcates basally delimiting the apron. There are conspicuous short vertical ridges at the labial crown base. These vertical ridges occasionally are amalgamated in smaller, probably juvenile teeth forming a short transversal crest similar to those found in Ptychotrygon.[1] The apron is broad, with a rounded extremity that is bent basally and is detached from the labial contour. The lingual face is fairly steep, and has a well-developed vertical directed uvula, above which is a well-marked central depression. This depression is bordered dorsally by a short and slightly convex transversal crest, which is constrained to the central cusp. The root is low and narrow, with narrow lobes separated by a broad, but deep central groove. There is no basal bulge.[1]

The teeth of Iberotrygon display some sort of ontogenetic variation. According to the available material, teeth of juvenile individuals seemingly differ from adult ones in the presence of amalgamated vertical ridges into short transversal crests and the presence of a vertical labial crest that tends to bifurcate basally in teeth of adults.[1]

Teeth of Iberotrygon resemble those of Ptychotrygon, and Archingeayia to some extent but can easily be distinguished from those by the character combination indicated in the diagnosis.[1][2][3]

References[]

  1. ^ a b c d e f Kriwet, Jürgen; Nunn, Elizabeth V.; Klug, Stefanie (2009). "Neoselachians (Chondrichthyes, Elasmobranchii) from the Lower and lower Upper Cretaceous of north-eastern Spain". Zoological Journal of the Linnean Society. 155 (2): 316–347. doi:10.1111/j.1096-3642.2008.00439.x.
  2. ^ Cappetta H, Case GR. (1999). Additions aux faunes de sélaciens du Crétacé du Texas. Palaeo Ichthyologica 9: 1–112.
  3. ^ Wueringer, B. E., Squire, L., & Collin, S. P. (2009). The biology of extinct and extant sawfish (Batoidea: Sclerorhynchidae and Pristidae). Reviews in Fish Biology and Fisheries, 19(4), 445.


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