THE SHARKS

.

Longfin mako
Isurus retroflexus (Agassiz)

Age - Miocene Commonality - Very uncommon

 The teeth of Isurus retroflexus are are similar to the Eocence mako Isurus praecursor. The distinguishing characteristic is a platform like margin on the labial side of the root.  The laterals have more globular crown tips and cusplets may be present even in large teeth from mature individuals.  The cutting edge is complete. I only have a few examples from New Jersey so I've included a type specimens of  I. retroflexus from Europe obtained thru trades.


 

Isurus retroflexus

Plate I.

Isurus retroflexus anterior tooth.
Identification verified by Bill Heim.

Monmouth County, NJ
 


 


The distinctive platform like margin on the labial side of the root.

 


 


Isurus retroflexus lateral, note the cusplets.
Labial view.
 


 


Another shot of the same teeth as above.
Left anterior measures xxx  and the lateral on the right xxx on the diagonal.
Monmouth County, NJ.

 


 


A few type specimens from my friends in Europe.
 


 

Return to top of page

Home Site Map Sharks