Ammonite Pair
from Madagascar
Madagascar Ammonites are from the Jurassic period (approximately 180 million years ago). Different Ammonite species were widely distributed during the Mesozoic era, about 200 million years ago. This era of geologic time includes the Triassic, Jurassic, and Cretaceous periods. During this period dinosaurs first appeared and then went extinct.
Ammonite fossils are a mineralized replacement of this ancient sea creature's shell. This particular Ammonite lived off the coast of Africa. Ammonites are an extinct mollusk, related to the nautilus, with a spiraling chambered shell. The chambers of this ammonite shell display perfectly shaped calcite crystals, which formed inside of these chambers. Ammonites are classified in the phylum Mollusca, class Cephalopoda, subclass Ammonoidea.
The dimensions of this ammonite pair is 17.5 x 14 x 2 centimeters. They weigh 500 grams, or just over one pound.
