Rare Microbajocisphinctes bigotoides Ammonite Fossil, Upper Bajocian Stage Jurassic, Authentic Evrecy Calvados France Collectors Specimen

Description

Authentic Jurassic Ammonite Fossil

This listing presents a genuine Microbajocisphinctes bigotoides Ammonite Fossil from the Upper Bajocian Stage of the Middle Jurassic, discovered in Evrecy, Calvados, France. Ammonites were extinct cephalopods related to squid and cuttlefish, characterised by their coiled, chambered shells that provided buoyancy for swimming. Fossils such as this are highly prized not only for their beauty but also for their scientific importance. The photographs show the exact specimen you will receive, with a 1 cm scale cube provided for accurate size reference.

Geological Context – Upper Bajocian, Jurassic

The Bajocian Stage (around 170–168 million years ago) marks a period of rich marine life during the Middle Jurassic. The Upper Bajocian, where this ammonite originates, is particularly important for ammonite evolution and biostratigraphy. The fossiliferous beds of Calvados in Normandy, France, have long been recognised as classic ammonite localities, producing exceptionally preserved specimens used to refine the Jurassic timescale.

Ammonites like Microbajocisphinctes bigotoides are considered index fossils, meaning they are invaluable for correlating rock layers across different regions. Their relatively short evolutionary lifespans and distinctive morphology allow paleontologists to establish precise ages for sedimentary deposits.

Species Profile – Microbajocisphinctes bigotoides

The species Microbajocisphinctes bigotoides belongs to the family Perisphinctidae, within the superfamily Perisphinctoidea and order Ammonitida. This genus is known for its small to medium-sized ammonites, often used in detailed stratigraphic studies due to their clear diagnostic features.

Notable traits of Microbajocisphinctes bigotoides include:

• A moderately evolute shell, with inner whorls visible in the umbilicus.
• Relatively fine, radial ribbing, often bifurcating or branching toward the venter.
• A rounded venter, sometimes with faint keel development.
• Proportionately wide umbilicus, exposing earlier growth stages of the shell.
• Intricate suture lines, typical of ammonites in the Perisphinctidae family.

These features make M. bigotoides an easily recognisable species and an important ammonite for Upper Bajocian stratigraphic frameworks.

Paleoenvironment and Scientific Importance

During the Middle Jurassic, the region that is now Normandy was submerged beneath shallow epicontinental seas connected to the Tethys Ocean. This warm marine environment supported diverse ecosystems with ammonites, belemnites, bivalves, and marine reptiles. Ammonites like Microbajocisphinctes bigotoides were nektonic predators, swimming actively and preying on smaller marine organisms.

After death, their shells settled onto the seabed, where burial in fine sediments ensured excellent preservation. The importance of M. bigotoides lies in its value for biostratigraphy, providing paleontologists with a tool to subdivide the Bajocian Stage into finer biozones and to compare rock 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 assures collectors that the ammonite is a true relic of Jurassic seas and not a cast or reproduction.

A Collector’s and Display Fossil

This Microbajocisphinctes bigotoides ammonite fossil from the Upper Bajocian of Evrecy, Calvados, France is a fine specimen that combines scientific relevance with natural beauty. Its provenance from one of Europe’s most celebrated Jurassic fossil sites, combined with its well-preserved ribbing and characteristic morphology, make it an exceptional piece for collectors, educators, and natural history enthusiasts.

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