Rare Hildaites merleyi Ammonite Fossil, Upper Toarcian Stage Jurassic, Authentic Deux Sevres France Collectors Specimen with COA

Description

Authentic Jurassic Ammonite Fossil

This listing is for a genuine Hildaites merleyi Ammonite Fossil from the Upper Toarcian Stage of the Early Jurassic period, discovered in Deux Sèvres, France. Ammonites are extinct marine cephalopods of the subclass Ammonoidea, close relatives of modern squid and octopus. They are among the most widely recognised fossils, celebrated for their spiral shells and role as important tools in dating and correlating Jurassic rock layers. This specimen has been carefully selected for its natural preservation and display quality. The photos provided show the actual fossil you will receive, with a 1 cm scale cube included for accurate sizing.

Geological Background – Upper Toarcian, Jurassic

The Upper Toarcian is part of the Early Jurassic period, dating to approximately 182–174 million years ago. It represents a significant interval in Earth’s history, following the Early Toarcian oceanic anoxic event that reshaped marine ecosystems. The ammonites from this stage are especially important for stratigraphic studies, as they evolved rapidly and are used to define precise biozones. The deposits of Deux Sèvres in western France were once shallow marine environments where fine sediments buried and preserved marine life, producing well-preserved fossils such as this ammonite.

Species Profile – Hildaites merleyi

The species Hildaites merleyi is part of the family Hildoceratidae within the superfamily Hildoceratoidea, order Ammonitida. Members of this family are known for their compressed shells, finely ribbed ornamentation, and elegant planispiral form. Hildaites species are particularly significant as zonal fossils for the Toarcian, with Hildaites merleyi associated with specific ammonite biozones in the Upper Toarcian of western Europe.

Morphological Features

This fossil displays the classic features of Hildaites merleyi, including:

• A compressed, planispiral shell with moderately involute coiling.
• Distinct, closely spaced ribbing that strengthens along the outer whorl.
• Visible suture lines, reflecting the intricate internal septal structure.
• A well-formed aperture, demonstrating the hydrodynamic adaptations of ammonites to active swimming in open seas.

These features help paleontologists identify the species and place it precisely within the Toarcian ammonite succession. For collectors, they add both scientific and aesthetic appeal.

Paleoenvironment and Scientific Value

The Upper Toarcian seas of what is now France were shallow marine basins that supported diverse ecosystems of invertebrates, fish, and reptiles. Ammonites such as Hildaites merleyi were nektonic predators, capable of moving swiftly through the water column. After death, their shells settled onto seabeds, where fine-grained sediments buried them quickly, leading to the preservation of detailed features.

Specimens like this are crucial for defining Upper Toarcian ammonite biozones, making them not only visually striking fossils but also valuable scientific markers. Their restricted stratigraphic distribution makes them excellent tools for geologists studying Jurassic sequences across Europe.

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 an authentic relic of the Jurassic seas of western France, preserved for nearly 180 million years.

A Collector’s and Display Piece

This Hildaites merleyi ammonite from Deux Sèvres, France is an excellent addition for fossil collectors, students of geology, and enthusiasts of natural history. Its combination of scientific importance, visual beauty, and secure provenance ensures it will stand out as a unique specimen in any collection.

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