SkaTES, RAYS and FISH

 

THE SAWFISH
Ischyrhiza mira (Leidy)

Age  Cretaceous - Occurrence  Common
 

The sawfish is not a shark but a skate. These somewhat common “teeth” that are collected in the streams of NJ are really the rostral spines that lined the elongated and flattened bill of the skate. These teeth are unique and not easily confused with any other species. I seem to have better luck finding these teeth scanning the gravel bars than I do screening. The oral teeth of Ischyrhiza mira can also be found. These teeth are small, normally less than 1/4 of an inch across and will fall through the standard 1/4 inch mesh screen. Because of their size it is difficult to determine just how scarce or common these teeth really are.  

A pristine rostral spine. Notice the distinct shape of the root and the
change in color at the tip of the blade
 

The rostral spines of the sawfish can get rather large and come in some
 unusual shapes. The distinctive root makes this an easy tooth to ID.
Scale 1 inch
 

The oral teeth of Ischyrhiza mira are small, normally less than 1/4
of an inch across and will fall through the standard 1/4 inch mesh
screen
 

The oral teeth have a deep nutrient grove in the root.
 

An assortment of oral teeth. This image gives a good indication of the
small size of these teeth
 

Rostal spines
 

Modern day sawfish rostrum

Return to top of page