Some Representative Invertebrates from the Cretaceous Period

Organization of This Section

There are twelve invert sections on the site:  

Ammonites (closed and open coiled, candy canes, and particularly weird forms), microfossils, annelid worms, jellyfish, belemnites (squid pens), brachiopods (lamp shells), corals, crustaceans (crabs, lobsters, and shrimp), echinoderms (urchins, sand dollars, starfish, brittle stars, and crinoids), gastropods (sea snails, conchs, and limpets), nautiloids (ancestors of the modern Nautilus) and pelecypods (clams, oysters, scallops, and rudistids). 

In order to highlight the relationships between members of these groups, we've organized each section taxonomically.  However, we've also made it easier to surf the site by adding quick reference galleries for all of the sections.

 General Information on the Stratigraphic and Geographic Distribution

• Ssynonyms as reported in the literature (most fossils have undergone extensive taxonomic reclassification over the years).
• Stratigraphic occurrence as reported in the literature.
• Age of the fossil, estimated by pinning it to known ammonite or bivalve age markers, "mya = millions of years ago".
• Geographic occurrence as reported in the literature.
• Additional remarks concerning taxonomic problems, and so forth.
• References that we found helpful in identifying the fossil.