Ammonite Fossil Jurassic 160 MYO Great Britain #16629 10o

Up for sale is a unique ammonite that you don’t see very often! It is a Brasilia bradfordensis ammonite from the Upper Inferior Oolite Group, Dorset, Great Britain. This ammonite dates back to the Jurassic Time Period approximately 160 million years ago and measures 4 inches. Ammonites were soft-bodied marine molluscs that lived in spiral, compressed, multi-chambered shells. The outermost chamber of the shell housed the animal itself. The earliest ammonites appeared during the Devonian time period, about 400 million years ago, and the last ammonites vanished in the Cretaceous time period, approximately 66 million years ago as a result of the K-T event that killed the dinosaurs. Ammonites are excellent index fossils, which means that the presence of a particular ammonite species in a geologic strata helps to identify the age of the fossils found in that layer. This is because certain species of ammonites only lived during specific time periods. Ammonites are sometimes confused with the similar-appearing nautilus. An ammonite can be distinguished from a nautilus by the pattern of its shell sutures, which are more complex and squiggly in the ammonite. This undulation in an ammonite’s sutures also creates a ribbed look to the outer surface of its shell, while the shell of the nautilus is smooth. We have a variety of ammonites available so be sure to check out our other listings!