Petalodont Teeth

Petalodont teeth are compressed and usually elongated compared to other Pennsylvanian and Permian shark teeth. The crown and root are commonly about equal length and there are commonly distinct ridges on the lingual (inner) side of the tooth where the crown and root meet. Few petalodont teeth have been found associated with other fish parts or as preserved cartilaginous imprints in black shale. Thus, little is known about the morphology of the petalodont fishes.

The teeth of Janassa are characterized by their "S-shaped" (sigmoid) outline when viewed laterally. Only a few examples of teeth attributable to Janassa have been found in Nebraska, but some more or less complete examples of janassiform fishes that superficially resemble skates or rays have been recovered from the Permian of Germany. Their teeth appear to be designed for crushing shells, and the stomach contents of specimens of Janassa bituminosa (Malzahn) from the Permian of Germany contained fragments of brachiopods, crinoids, foraminifers, and crabs.

Petalodont Teeth
  • Species Name: Janassa sp. cf. maxima
  • Date: 8/9/2006
  • Database ID: 61
  • Description: "Janassa" sp. cf. "maxima"
Petalodont Teeth
Petalodont Teeth
  • Species Name: Serratodus? sp.
  • Date: 8/8/2006
  • Database ID: 56
  • Description: This tooth is compared to the genus "Serratodus" that was described from the much older lower Carboniferous (Mississippian) of Belgium. The tooth has the same general oval outline with a short root and crown as "Serratodus" but lacks the serrations on the crown.
Petalodont Teeth
Petalodont Teeth
  • Species Name: Chomatodus sp.
  • Date: 8/8/2006
  • Database ID: 55
  • Description: "Chomatodus" teeth suggest that it was a shell crusher. "Chomatodus" is a very long ranging genus (Devonian Permian) that had a broad geographic distribution (USA, Canada, Ireland, and European Continent).
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/28/2006
  • Database ID: 30
  • Description: Tiny teeth of Petalodus sp. cf. destructor have been interpreted as both the cutting tooth of a predator that stalked large prey, and as a pavement tooth that served to crush shells of invertebrates. It may be that P. destructor had an unspecialized diet and that it fed on both large prey and small invertebrates.
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/27/2006
  • Database ID: 27
  • Description: Tooth from mature individual of "Petalodus" sp. cf. "destructor".
Petalodont Teeth
Petalodont Teeth
  • Species Name: Janassa sp. cf. maxima
  • Date: 7/27/2006
  • Database ID: 26
  • Description: "Janassa" sp. cf. "maxima"
Petalodont Teeth
Petalodont Teeth
  • Species Name: Janassa sp. cf. maxima
  • Date: 7/27/2006
  • Database ID: 25
  • Description: "Janassa" sp. cf. "maxima"
Petalodont Teeth
Petalodont Teeth
  • Species Name: Janassa sp. cf. maxima
  • Date: 7/27/2006
  • Database ID: 24
  • Description: "Janassa" sp. cf. "maxima"
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/27/2006
  • Database ID: 23
  • Description: Lateral tooth of "Petalodus" sp. cf. "destructor".
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/27/2006
  • Database ID: 22
  • Description: Tooth from mature individual of "Petalodus" sp. cf. "destructor".
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/27/2006
  • Database ID: 21
  • Description: Tooth from mature individual of "Petalodus" sp. cf. "destructor".
Petalodont Teeth
Petalodont Teeth
  • Species Name: Petalodus sp. cf. destructor
  • Date: 7/27/2006
  • Database ID: 20
  • Description: Tooth from mature individual of "Petalodus" sp. cf. "destructor".
Petalodont Teeth