SKATES, RAYS and BONEY FISH

 

WHIPTAIL STINGRAY
Dasyatis sp. (RAFINESQUE, 1810)

Age  Late Cretaceous - Present - Occurrence  Common

( Common terms for ray teeth )

  Over twenty species have been report with the earliest coming from the Late Cretaceous. The assignment
of some of these species to the genus Dasyatis is questionable (Cappetta, 1987). I've made no attempt to assign
the examples on this page to a particular species.
  The teeth of this genus are small (2-5 mm) and have a very distinctive shape. When viewed on profile the  root juts out well past the crown.  The root has a deep nutrient grove and either a large central foramen or a group of smaller foramina. There is a marked difference between female and male teeth. Female teeth have a globular crown with a prominent transverse ridge while the male cusp is high and lacks the transverse ridge. Speaking from my own experience, the female teeth are much more common then the male. Of my 15+ Dasyatis specimens only 2 are males.

 


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Dasyatis sp.


Dasyatis sp. female
These teeth are small (2-5mm), about 1/8 of an inch across.
This example perched on a US dime is only 2 mm across.
 


 


Plate 1 - Dasyatis sp. Female
Left to right, top to bottom
lingual, labial, profile, occlusal, basal

Monmouth County, NJ


 


All the examples I've found have two or more foramina. These can be
seen as small holes in the grove of the root. Often these become filled with
sediment and may be difficult to spot.


 

Profile view showing the transverse ridge.

 


 

Plate 3
Dasyatis sp.
male or breeding tooth.
Most reference material refers to this tooth design as a male Dasyatis, it's
certainly worth noting an alternative theory that these
are male breeding-season teeth.
 


Selected References

Cappetta, H., 1987. Chondrichthyes II: Mesozoic and Cenozoic Elasmobranchii. Handbook of Paleoichthyology, 3B. Gustav Fischer Verlag, Stuttgart and New York, 193 pp.

 

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