RARE 5″ Erymnoceras leuthardi Fossil Ammonite Middle Callovian Jurassic France – Genuine Authentic Prehistoric Marine Cephalopod with COA

Description

Rare Middle Jurassic Ammonite from France

This is a rare 5-inch Erymnoceras leuthardi fossil ammonite from the Middle Callovian stage of the Jurassic period, discovered near Sées in France. It is a beautifully preserved and carefully selected specimen, notable for its distinctive ribbing, exceptional form, and strong visual appeal. The photographs provided show the exact fossil you will receive, ensuring authenticity and transparency for collectors and enthusiasts.

Geological Age & Formation

Erymnoceras leuthardi lived during the Middle Callovian stage, approximately 164.7 to 161.2 million years ago. At this time, the area that is now north-western France lay beneath shallow, warm seas teeming with marine life. Fine-grained marine sediments buried ammonite shells quickly after death, preserving their intricate structures in remarkable detail. The fossil-rich deposits of the Sées region are well known for producing ammonites of exceptional scientific and aesthetic quality.

Species Identification & Morphology

Belonging to the family Stephanoceratidae within the superfamily Stephanoceratoidea and order Ammonitida, Erymnoceras leuthardi is distinguished by its moderately involute shell, strong and regularly spaced ribbing, and occasional tuberculation along the flanks. The whorls are broad, and the ribs typically bifurcate towards the outer edge, creating a graceful yet robust appearance. The suture lines, a hallmark of ammonite identification, are complex and well-defined in this specimen, reflecting its advanced evolutionary stage.

Collector Highlights

• Size: Approximately 5 inches across (scale cube in photos = 1 cm squares for accurate measurement).
• Preservation: Outstanding detail with crisp ribbing, clear suture patterns, and excellent shell form.
• Authenticity: Guaranteed 100% genuine fossil, supplied with a Certificate of Authenticity.
• Display Quality: Attractive, well-prepared piece ideal for display in a cabinet, study, or educational setting.
• Rarity: Erymnoceras leuthardi is less common on the open market than many other Jurassic ammonites, making this a valuable acquisition.

Paleoenvironment & Scientific Significance

During the Middle Callovian, Erymnoceras species inhabited warm, shallow epicontinental seas where they thrived as nektonic predators. They likely fed on small crustaceans, mollusks, and other invertebrates, using tentacles to capture prey and a powerful beak-like jaw to process it. The shell’s internal chamber system (phragmocone) enabled buoyancy control, allowing precise movement through the water column.

Ammonites such as Erymnoceras leuthardi are important index fossils, helping geologists and paleontologists to date and correlate marine sedimentary rock layers across Europe. Their distinctive ribbing patterns, shell proportions, and suture designs make them critical in refining the biostratigraphic framework of the Jurassic.

A Premier Addition to Any Collection

This Erymnoceras leuthardi ammonite represents a tangible connection to the Jurassic seas that once covered much of Europe. Its combination of rarity, scientific value, and natural beauty ensures it will be appreciated as both a display piece and a significant fossil for study. It is suitable for advanced fossil collectors, geology enthusiasts, educators, and as a truly unique natural history gift.

All of our fossils are 100% genuine specimens and come with a Certificate of Authenticity. The fossil pictured is the exact specimen you will receive.