BHI Catalog:  Invertebrates:  Mollusks

  Mollusks

There are ten classes of mollusks, of these eight are still living. This diverse group of animals includes varieties from deep sea worm-like creatures, to clams and snails, to the colorful and strange cephalopods. Mollusks first appeared in the Middle Cambrian period over 500 MYA in the Burgess Shale. Living cephalopods like the octopus, cuttlefish and squid have a shell that has been internalized, while the nautilus shell is external. Ammonoid cephalopods first appeared in the fossil record about 400 MYA, and became extinct at the end of the Cretaceous. Ammonoid cephalopods  had a hard external shell like the nautilus, however they were more closely related to the squid and octopus. Today these mollusks, both extinct and extant, are admired and valued for their beautiful, varied and colorful shells.

Subcategories
Show All Items in Subcategories
South Dakota
South Dakota is known for an abundance of ammonite fossils, which were predatory, but few reached a size that would place them at the top of the food chain.
 
On-line Catalog
Catalog Home

-Dinosaurs & Birds
-Reptiles & Amphibians
-Mammals
-Fishes
-Invertebrates
-Plants & Amber
-Meteorites
-Media & Displays
-Fossil Work Supplies
-Fossil Art & Collectibles
-Books, Videos, Posters & Charts
-Gifts & Apparel


Indexes
Catalog Index
Original Specimens
Catalog & BHI PDFs


Search
Search Catalog



Programs & Services
Lease Program


Your Cart
Cart is Empty

View Cart
Checkout


Account Login
Username

Password

Log in
Register
Recover password



Help
Contact Us
Privacy Statement
Terms & Conditions



Map ~ Help ~ Links