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 Annie Henderson '01
Geology & Environmental Studies Major

 SHARK FOSSILS

The shark fossils found on the fieldtrip could be classified into two genera. The teeth can be placed in a specific group while there is no way to distinguish the genus and species of the vertebrae or coprolites. The following chart best describes the possible identifications of the fossils and some corresponding details.

 Name  Coprolites
 Age  Late Cretaceous
 Formation  Main Fossiliferous Layer
 Comments

   The coprolites could be produced by either Scapanorhycus texanus or or S.qualicorax pristodontus  (though not S.qualicorax kaupi, which is only found below the Navesink Formation). It is impossible to distinguish which group produced the fossilized fecal matter.

   Spiral patterns and parallel vertical grooves on each spiral found on the surface of the coprolite are artifacts of the spiral intestine of the responsible shark.

 Name  Shark Vertebrae
 Age  Late Cretaceous
 Formation  Main Fossiliferous Layer
 Comments

   There are two types of shark vertebrae found in New Jersey. Both schliorhynoid and lamnoid vertebrae are cylindrical with cone shaped depressions in either side.

Schliorhynoid has two openings on both the top and bottom, which allowed for the elongation of cartilage to connect to muscle attachments. Lamnoid have several openings on the sides as well as 4 main holes and are generally larger than schliorhynoid vertebrae.

According to Yoost's website, the number of concentric rings on a vertebrae act as age determinants, much like tree rings.

 Name  Shark Tooth
 Age  Late Cretaceous
 Formation  Main Fossiliferous Layer
 Comments

   Teeth are the most common fossils of paleosharks because they are the only true bones of the cartilaginous fish (the skeleton is made up of cartilage).

   This is an anterior, lower tooth of S. texanus. The bilateral roots have been broken off, though the longitudinal striations are still apparent. The striations are the main characteristic of the main cusp of the tooth. This tooth varies greatly from the triangular, flattened upper and lower lateral teeth and the slanted, shorter posterior teeth.

 

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