Ammonite Fossil  - cca 11x8 cm 
 This is a beautiful,  polished ammonite (Argonauticeras) fossil from the Mahajanga Province of Madagascar. It is Early Cretaceous (Albian Stage) in age, or approximately 110 million years old. This is one of the more uncommon ammonite genera found in the area.

Ammonites were predatory mollusks that resembled squids with shells. These cephalopods had eyes, tentacles, and spiral shells. Though their shells resemble that of a nautilus, they are actually more closely related to living octopuses. Ammonites appeared in the fossil record about 240 million years ago, barely surviving several major extinction events. The last lineages disappeared 65 million years ago at the end of the Cretaceous.