Vertebrate fossils generally are not common in NJ, with the exception of shark teeth. These are
most often found by sifting sediment through a wire mesh screen. Most of the teeth are Cretaceous
or Paleocene in age, however, Eocene and Miocene teeth have been found at a few localities.

Sharks have a skeleton which is composed entirely of cartillage. Cartillage is rarely preserved unless it has been petrified. Usually only the vertebra centra, dermal denticals, and fin spines are preserved.

Sometimes bony fish are found alone with shark teeth, though are usually less common or very small. Sometimes jaws with the teeth still are found. Common Cretaceous bony fish include Enchodus and Anomeoudus.
 

From upper left to lower right: Squalicorax kaupi, Scapanorhyncus texanus  tooth, Scapanorhyncus texanus upper, Xiphactinus  audax, Cretolamna sp., Cretolamna appendiculata,  Enchodus ferox, Otodus obliques

Besides the remains of fish teeth, other vertebrate fossils are sometimes found, mostly reptile.
Shell fragments are not uncommon, especially at the K/T bone bed between the Navesink and Hornerstown formations. This bed has produced most of the complete turtle and crocodile
skeletons found in NJ. Crocodile and mosasaur bones and teeth, highly prized among
collectors, are scarce. Dinosaur fossils from the Cretaceous are extremely rare, since NJ
was under water during most of this period. Footprints from the Triassic period have been
in large numbers in northern NJ, however almost no bone material has been found.
Three partial skeletons have been found during over 150 years of collecting. Since the
decaying corpses had to be transported for miles from rivers or estuaries, they normally
would have been torn apart by scavengers, such as sharks. Thus, only exceptional
circumstances would allow a relatively complete dinosaur such as Hadrosaurus foulkii to
be buried quickly enough in marine sediments to be preserved.
 
 

Several crocodile scutes, which served as armor on the back and head of the animal

 

A partial crocodile jaw

The rarest fossils found in the Cretaceous of NJ are those of birds and mammals.
The bones of both were very small and delicate, hindering preservation. The teeth
of mammals are especially difficult, since most are so small they require a powerfull
hand lens or microscope to be identified.
 
 

A mosasaur tooth