Rare Pseudogrammoceras Ammonite Fossil, Middle Toarcian Stage Jurassic, Authentic Aveyron France Collectors Specimen with COA

Description

Genuine Jurassic Ammonite Fossil

This listing features a genuine Pseudogrammoceras Ammonite Fossil from the Middle Toarcian Stage of the Early Jurassic, discovered in Aveyron, France. Ammonites are extinct marine cephalopods of the subclass Ammonoidea, related to squid and cuttlefish. Their spiral shells with intricate chambered structures make them among the most iconic fossils in the world. This specimen has been carefully chosen for its preservation and clarity, with photographs showing the exact ammonite you will receive. A 1 cm scale cube is provided to give precise sizing.

Geological Context – Middle Toarcian, Jurassic

The Middle Toarcian, dating to approximately 178–177 million years ago, represents a key interval in the Early Jurassic. It followed the Early Toarcian Oceanic Anoxic Event, a global climatic and environmental episode that dramatically affected marine ecosystems. The fossil-rich beds of Aveyron are particularly renowned for their preservation of ammonites, capturing these creatures in remarkable detail.

Ammonites from this stage are highly significant in stratigraphy, as they serve as index fossils. Their rapid evolutionary turnover and wide distribution enable paleontologists to subdivide the Jurassic into precise ammonite zones. Fossils like Pseudogrammoceras are invaluable for correlating rock sequences across Europe.

Species Profile – Pseudogrammoceras

The genus Pseudogrammoceras belongs to the family Graphoceratidae, within the superfamily Hildoceratoidea and order Ammonitida. These ammonites are known for their refined, compressed shell forms, elegant ribbing, and their importance in Toarcian ammonite faunas.

Key identifying traits of Pseudogrammoceras ammonites include:

• A moderately evolute shell, leaving earlier whorls partially visible.
• Fine, closely spaced ribbing running across the flanks.
• A keel along the venter, improving hydrodynamic efficiency.
• Distinct suture patterns marking the internal septal divisions of the chambers.

These features provide both aesthetic appeal for collectors and scientific value for researchers working on Jurassic stratigraphy.

Paleoenvironment and Scientific Importance

During the Middle Toarcian, the Aveyron region of France lay beneath warm, shallow seas. Ammonites like Pseudogrammoceras thrived as nektonic predators, actively swimming in the water column and preying on smaller marine organisms. After death, their shells settled onto the seafloor, where fine-grained sediments quickly buried them, allowing their preservation over millions of years.

Pseudogrammoceras ammonites are particularly important in defining biozones within the Toarcian Stage. Their relatively narrow stratigraphic range allows geologists to date and correlate rocks with precision. For collectors, this means owning not only a fossil of striking beauty but also one with a direct connection to Earth’s geological history.

100% Genuine with Certificate of Authenticity

All of our fossils are guaranteed 100% genuine specimens and include a Certificate of Authenticity. This ammonite is not a cast or reproduction but a true relic of the Jurassic seas, preserved for over 177 million years.

A Collector’s and Display Fossil

This Pseudogrammoceras ammonite fossil from the Middle Toarcian of Aveyron, France is a superb addition to any fossil collection, educational display, or natural history showcase. With its elegant ribbing, scientific importance, and authentic provenance, it is a specimen of both scholarly and aesthetic value.

Scale Rule Squares / Cube = 1 cm. Please see listing photos for the full sizing of this exact specimen.