Invertebrate Fossils of NJ
Ammonites were hard shelled squid-like marine
animals that existed from the Paleozoic to the end of the Cretaceous era
when they suddenly became extinct. Some ammonite fossils bear intricate
patterned details on their outer surface called sutures. These are
located beneath the external shell wall, and are often visible if the
fossil has been subject to weathering or polishing. These patterns mark
where the walls of the chambers and the outer wall of the shell meet.
In the streams of NJ we find mostly fragments of these chambers. The
first one I found took a while for me to identify. A number a different
species have been found in the NJ area.
Fossilized ammonite chamber.
Surface sutures on a polished ammonite
Two chamber fragments still joined together,
This ammonite is about half complete
An ammonite from Germany from my personal collection