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

Description

Authentic Jurassic Ammonite Fossil

This listing presents a genuine Harpoceras subexartus Ammonite Fossil from the Middle Toarcian Stage of the Early Jurassic period, discovered in Aveyron, France. Ammonites were extinct marine molluscs belonging to the subclass Ammonoidea, closely related to squid and cuttlefish. Their spiral, chambered shells are among the most distinctive and widely collected fossils in the world, valued for their scientific significance and aesthetic appeal. The specimen shown in the photographs is the exact fossil you will receive, with a 1 cm scale cube provided for size reference.

Geological Context – Middle Toarcian, Jurassic

The Middle Toarcian, dating to around 178–177 million years ago, followed the Early Toarcian Oceanic Anoxic Event, a major global environmental event that significantly influenced marine life. During this time, ammonites thrived and diversified, leaving behind a rich fossil record. The Aveyron region of southern France is particularly famous for its fossiliferous marine deposits, which preserve ammonites with remarkable detail.

Ammonites from this stage are of great importance in geology because they act as index fossils, allowing precise subdivision of the Jurassic into ammonite zones. The presence of Harpoceras subexartus helps paleontologists correlate strata across Europe, making it scientifically valuable as well as a highly desirable collector’s specimen.

Species Profile – Harpoceras subexartus

The species Harpoceras subexartus belongs to the family Hildoceratidae, within the superfamily Hildoceratoidea and order Ammonitida. This genus is notable for its compressed shell structure, pronounced ribbing, and sharp keel, making it both a distinctive and scientifically significant ammonite.

Key identifying features of Harpoceras subexartus include:

• A compressed, planispiral shell with moderately involute coiling.
• Prominent ribbing across the flanks, often branching as it approaches the venter.
• A well-defined keel running along the venter, a common feature in the genus.
• Complex suture patterns that highlight the internal septal architecture of the shell.

These features make Harpoceras subexartus both scientifically valuable for stratigraphic studies and visually appealing for display in collections.

Paleoenvironment and Scientific Importance

During the Middle Toarcian, the region that is now Aveyron was covered by shallow, warm seas. Ammonites such as Harpoceras subexartus lived as nektonic predators, swimming actively in the water column and preying on smaller marine organisms. Upon death, their shells settled on the seafloor, where they were buried in fine-grained sediments, allowing for fossilisation over millions of years.

This species is particularly important for paleontologists because its restricted stratigraphic distribution makes it a valuable biozonal marker. Its presence allows for precise geological dating and correlation of Jurassic deposits across Europe, reinforcing its scientific importance as well as its role as a highly sought-after collector’s fossil.

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 replica or cast but an authentic relic of Earth’s Jurassic seas, preserved for nearly 180 million years.

A Collector’s and Display Fossil

This Harpoceras subexartus ammonite fossil from the Middle Toarcian of Aveyron, France is an excellent specimen for collectors, educators, and enthusiasts of natural history. Its scientific value, combined with its distinctive morphology and excellent provenance, make it a standout addition to any collection or display.

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