Rare Pseudogrammoceras reynesi Ammonite Fossil, Middle Aalenian Stage Jurassic, Authentic Caen France Collectors Specimen with COA

Description

Authentic Jurassic Ammonite Fossil

This listing offers a genuine Pseudogrammoceras reynesi Ammonite Fossil from the Middle Aalenian Stage of the Jurassic period, discovered in Caen, France. Ammonites were marine cephalopods belonging to the subclass Ammonoidea, close relatives of modern squid and octopus. Their spiral, chambered shells are some of the most recognisable and widely collected fossils, valued for both their beauty and their importance in geology and paleontology. This specimen was carefully selected to showcase the natural characteristics of the species. The photographs provided show the exact ammonite you will receive, with a 1 cm scale cube included for reference.

Geological Context – Middle Aalenian, Jurassic

The Aalenian Stage, spanning approximately 174–170 million years ago, represents the earliest stage of the Middle Jurassic. This period was marked by widespread shallow seas that extended across much of Europe, providing the perfect environment for ammonites to flourish. The deposits around Caen in Normandy are particularly well known for their fossiliferous limestones and marls, which preserve ammonites in excellent condition.

Ammonites from the Aalenian are especially significant because they serve as index fossils. Their rapid evolutionary changes and global distribution make them critical tools for defining biozones and correlating strata across regions. Specimens such as Pseudogrammoceras reynesi are therefore not only visually impressive but also scientifically invaluable.

Species Profile – Pseudogrammoceras reynesi

The species Pseudogrammoceras reynesi belongs to the family Graphoceratidae, within the superfamily Hildoceratoidea and order Ammonitida. Members of this family are distinguished by their elegant ribbing and well-defined coiling.

Key features of Pseudogrammoceras reynesi include:

• A moderately evolute, planispiral shell with visible inner whorls.
• Fine, regular ribbing running across the flanks towards the venter.
• A smooth keel along the venter, contributing to its hydrodynamic form.
• Clearly defined suture lines that highlight the internal septal structure.

These characteristics make Pseudogrammoceras reynesi an excellent marker for Aalenian ammonite faunas, while also ensuring its aesthetic appeal as a collector’s fossil.

Paleoenvironment and Scientific Importance

During the Aalenian, the Caen region of France was covered by shallow, warm seas. Ammonites such as Pseudogrammoceras reynesi lived as nektonic predators, actively swimming through the water column and feeding on smaller marine organisms. After death, their shells sank to the seafloor, where they were quickly buried in sediments. Over millions of years, these sediments lithified, preserving the ammonites as fossils.

Pseudogrammoceras reynesi is particularly important for paleontologists because of its stratigraphic utility. Its restricted range within the Middle Aalenian allows researchers to date rocks with precision and to correlate layers between different geographic regions. For collectors, this means owning a fossil with not only aesthetic charm but also profound scientific value.

100% Genuine with Certificate of Authenticity

All of our fossils are guaranteed 100% genuine specimens and come with a Certificate of Authenticity. This ammonite is not a cast or reproduction but a true relic of the Jurassic seas of Caen, preserved for over 170 million years.

A Collector’s and Display Fossil

This Pseudogrammoceras reynesi ammonite fossil from Caen, France is an exceptional addition for fossil enthusiasts, geology students, and natural history collectors. Its scientific importance, elegant ribbing, and distinctive Jurassic provenance ensure it will be a standout specimen in any collection or display.

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