Extinct Mackerel Shark
Xiphodolamia ensis (Leidy)

Age - Eocene  Commonality - Uncommon

Xiphodolamia ensis, also know as the extinct mackerel shark was a deep water dweller that lived during the Eocene. These teeth are scarce worldwide, and in North America are only found on the east coast. The anterior teeth of Xiphodolamia ensis are unique in that the cutting edge is on the labial and sometimes lingual side of the crown. The lateral teeth posse a triangular shaped crown with a distinct root which is highly compressed and slopes back from the lingual side of the tooth. Finding these teeth in NJ falls somewhere between uncommon and scarce.
 


 

Two different views of the same anterior tooth showing the unique
cutting edge
Monmouth County, NJ
 


 

The roots of the anterior teeth have a rather unusual
“swept back” appearance.
 


 

This small anterior tooth has a partial cutting edge on the lingual
side of the crown.
 


 

Xiphodolamia ensis

Lateral tooth from several angles
 


 

Lateral-anterior and anterior teeth


 

An assortment of Xiphodolamia ensis.
Monmouth County, NJ.
 

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