Although relatively simple in form, ammonites are extremely rich in the information they yield to scientists. These extinct marine animals, which thrived in the Paleozoic and Mesozoic Eras, some 400 to 465 million years ago, were cephalopods, and are thus related to squid, octopus, cuttlefish, and the chambered nautilus.
Ammonites were able to swim, thanks to the unique construction of their shell, which was divided into a series of air chambers. The air in the chambers provided buoyancy for the animal to float; like modern cephalopods, they probably moved through the water using jet propulsion.
As different species of ammonites lived during different time periods, scientists can use these animals to determine the relative age of the rocks in which their fossils are found ("index fossils"). Because ammonites lived exclusively in marine environments, their presence also indicates the location of prehistoric seas.
FREE FedEx Ground shipping within the (48) Continental United States!
To all our Alaska, Canada and Hawaii customers: you will be notified of any applicable shipping charges prior to processing your order for approval.
|