Hildoceras crassum Ammonite Fossil Middle Toarcian Jurassic Aveyron France Genuine Specimen

Description

Genuine Hildoceras crassum Ammonite Fossil from Aveyron, France

This authentic Hildoceras crassum ammonite fossil comes from the Middle Toarcian stage of the Jurassic Period, approximately 181–174 million years ago, and was discovered in the classic fossil-rich strata of Aveyron, France. Known for its distinctive ribbed shell and scientific importance, this species of ammonite is a highly valued specimen for collectors, paleontologists, and enthusiasts of Earth’s ancient history. Each fossil is carefully chosen and supplied with a Certificate of Authenticity, ensuring its provenance and genuine nature. The exact specimen photographed is the one you will receive.

Geological Context and Formation

The Toarcian stage, part of the Early Jurassic, is one of the most studied intervals in geological history. This ammonite fossil originates from the Middle Toarcian, a period defined by fluctuating sea levels, evolving marine ecosystems, and the aftermath of the Toarcian Oceanic Anoxic Event, a significant climatic and oceanographic event that had global impact.

The marine deposits of Aveyron consist of marls and limestones, formed in shallow, warm seas connected to the ancient Tethys Ocean. These conditions favoured the preservation of ammonites, providing highly detailed shells that have endured for millions of years. Fossils from this area provide key evidence for understanding Jurassic stratigraphy and paleoecology.

Scientific Classification

• Class: Cephalopoda
• Subclass: Ammonoidea
• Order: Ammonitida
• Superfamily: Hildoceratoidea
• Family: Hildoceratidae
• Genus: Hildoceras
• Species: Hildoceras crassum

Members of the genus Hildoceras are important index fossils, widely used in correlating sedimentary layers across Europe. Their abundance, rapid evolution, and distinctive morphology make them indispensable tools for geologists reconstructing the Jurassic timescale.

Morphological Features and Distinctive Traits

The Hildoceras crassum ammonite is characterised by its robust, moderately involute shell with thick, coarse ribbing that extends across the flanks and crosses the venter. The whorls are relatively compressed, giving the fossil a strong, angular appearance that distinguishes it from more delicate ammonite species. The ribs are often widely spaced, producing a bold and easily recognisable shell ornamentation.

These structural features not only add to the visual appeal of the fossil but also reveal insights into the hydrodynamic adaptations of the species. Like other ammonites, Hildoceras crassum likely lived as a free-swimming predator in open marine waters, preying on small fish, crustaceans, and planktonic organisms. Its ribbed shell may have provided both strength and hydrodynamic stability in the Jurassic seas.

Paleoecological and Scientific Importance

Ammonites such as Hildoceras crassum play a vital role in the biostratigraphic zonation of the Middle Toarcian. Their relatively short evolutionary lifespan, combined with widespread distribution, makes them excellent markers for dating Jurassic deposits across Europe and beyond.

The fossil record of Hildoceras also provides important information about the ecological recovery of marine faunas following the environmental stress of the Toarcian Oceanic Anoxic Event. Their presence in the Aveyron deposits indicates the resilience and adaptability of ammonites in fluctuating marine conditions.

A Fossil of Scientific and Display Value

This Hildoceras crassum ammonite fossil from Aveyron is not only a scientifically important specimen but also a visually striking piece of natural history. The bold ribbing and well-preserved shell structure make it an attractive fossil for display, while its stratigraphic and paleontological significance add value for researchers and collectors alike.

Each specimen comes with a Certificate of Authenticity, and the photographs show the exact fossil you will receive. With its combination of geological history, scientific importance, and aesthetic appeal, this ammonite makes an exceptional addition to any fossil collection.