FOSSILS OF NEW JERSEY
Extinct Shortfin Mako
Age - Miocene Commonality - Uncommon
Two species of mako have been reported from New Jersey; Isurus praecursor from the Eocene and Isurus desori from the Miocene, both belonging to the group of extinct narrow-toothed mako sharks. The teeth of Isurus desori are fairly large, averaging over an inch in length and reaching a maximum length of well over of 2 inches. When compared to other teeth from Monmouth County these teeth are relatively robust and except for juveniles have no cusplets. A nutrient grove is lacking, or a best shows as a weak depression. On specimens that are not too stream worn nutrient pores may be present, these may form what looks like a single opening due to clustering and/or stream wear. The lateral teeth of Isurus desori and Isurus praecursor are almost indistinguishable. Large sand tigers that are missing their cusplets may also be mistaken for makos.
Anterior and lateral teeth of
The two largest anterior teeth I have found to date. both teeth are just
over two inches in length.
Lateral teeth if
Isurus desori. The roots on the lateral
Nutrient pores forming a single hole