Arietites bucklandi F2

This fossil specimen is a perfect example of Arietites bucklandi, a species of extinct marine cephalopod and a classic “index fossil”. Its presence in rock layers allows geologists to pinpoint the age of the surrounding strata with remarkable accuracy, as it marks the Bucklandi Zone of the Early Jurassic Period, roughly 150 million years ago.

This fossil’s prominent features are its massive, evolute whorls and the deep, radiating ribs that are characteristic of the Arietites genus. Unlike some other ammonites, its shell is not tightly coiled, and it features a distinctive keel with two longitudinal grooves running along its outer edge.

This particular specimen, sourced from France, is an ideal piece for any serious collection.