Belemnitella americana (Morton)
to a diverse group of
cephalopods which include the squid, cuttlefish and octopus,
they are characterized by an internally chambered shell known as a guard. Looking
like bullets or orange pens,
is found in abundance at the Big Brook Fossil Preserve. The forward part of the guard (the back is the
pointed end) has a V shaped chamber which was used for buoyancy control.
Casts of these chambers called phragmocones
are often mistaken for teeth. Belemnites
can occur in huge numbers in some localities in so-called belemnite
(Richards et al,
1962) only lists this single species as being present in New Jersey.
These specimens have been polished up a bit.
Monmouth County, NJ
These belemnites were found split like this. This
gives a good view of the chamber
used for buoyancy control.
Internal casts of the chambers are common and easily mistaken for teeth
Unlike shark teeth the casts are "cone like" with two ridges running
down the sides.
A group of larger beleminites, the top one measures 4
In New Jersey the belemnite guard is usually amber colored, due to
absorption of iron.
Richards, H., R. Ramsdell, A. Miller, H. Garner, J. Reeside Jr., A.
Jeletzky, H. Roberts, and H. Miller Jr. 1962. The Cretaceous Fossils of
New Jersey, Part
II. Bulletin 61, Bureau of Geology and Topography, Department of
Conservation and Economic
Development, Trenton, NJ, 237 pp.