Gorgeous example of an opalized ammonite fossil in matrix.
1.75 x 1.75 x 1.5 inches
Upper Cretaceous period, 145 to 66 million years ago. Sourced N. Central South Dakota
.75 x 3 inches diameter
Ammonites are perhaps the most widely known fossil, possessing a typically ribbed spiral-form shell. These creatures lived in the seas between 240 – 65 million years ago, when they became extinct along with the dinosaurs. The name ‘ammonite’ originates from the Greek Ram-horned god called Ammon. Ammonites belong to a group of predators known as cephalopods, which includes their living relatives the octopus, squid, cuttlefish and nautilus
In North America, Crow, Sioux, and other Great Plains tribes often found such fossils, relics of the sea that once covered the continent’s western interior and used these “stones” to heal injuries and to bring good fortune in marriage, hunting, travel, and warfare.