Ammonites & Orthoceras

Ammonites and orthoceras are among the most recognizable fossils in the world — ancient marine cephalopods that swam the Earth’s oceans for hundreds of millions of years. Our collection features polished and natural specimens that preserve the spiral chambers of ammonites and the elongated shells of orthoceras in stunning geological detail.
Ammonites first appeared approximately 400 million years ago during the Devonian period and thrived until the end-Cretaceous extinction event 66 million years ago. Their coiled shells were divided into gas-filled chambers that the animal used for buoyancy control — similar to the modern nautilus. Orthoceras, the straight-shelled relatives, are even older, with some specimens dating back over 450 million years to the Ordovician period. When these animals died and settled on the ocean floor, their shells were gradually replaced by minerals, preserving intricate structural details.
Many of our ammonite specimens come from Madagascar, where erosion exposes beautifully preserved fossils with iridescent nacre surfaces. Orthoceras specimens from Morocco’s Atlas Mountains are equally impressive, often found in polished black limestone that highlights the white fossil forms. These fossils make exceptional display pieces, educational tools, and conversation starters. Browse our collection to find ammonite and orthoceras specimens that connect your collection to deep geological time.