RARE Bigotites thevenini Fossil Ammonite – Upper Bajocian, Jurassic, Calvados France – Genuine + COA

Description

An exceptionally rare and well-preserved Bigotites thevenini Fossil Ammonite, from the Upper Bajocian Stage of the Jurassic Period, collected in Calvados, Normandy, France. This ammonite is a true collector’s piece, representing a less commonly encountered genus with distinctive ribbing and stratigraphic importance. Comes with a Certificate of Authenticity, and the exact fossil pictured is the one you will receive.

Fossil Type & Species:

• Type: Ammonite (extinct marine cephalopod)
• Species: Bigotites thevenini
• Order: Ammonitida
• Superfamily: Stephanoceratoidea
• Family: Stephanoceratidae

Geological Context:

• Period: Jurassic
• Epoch/Stage: Middle Jurassic – Upper Bajocian (approx. 170.3 to 168.3 million years ago)
• Biozone: Likely from the Parkinsonia or Garantiana zone (Bigotites often associated with finer zonal subdivisions in regional stratigraphy)
• Depositional Environment: Marine shelf environment with alternating marl and limestone beds – rich in cephalopod fauna

Locality:

• Region: Calvados, Normandy, France
• Formation: Bajocian limestone-marl sequences of the Paris Basin (formation unconfirmed)

Morphology & Features:

• Strongly evolute shell with broad umbilicus
• Sharp, widely spaced ribs, with occasional tuberculation
• Flanks relatively flat; ribs extend across the venter without interruption
• Characteristic of Bigotites, which is distinguished from contemporaneous forms by its ornamentation pattern

Scientific Notes:

• Bigotites thevenini was described by de Grossouvre and named in the early 20th century
• A rare genus important for understanding evolutionary transitions within Stephanoceratidae during the Bajocian

Notable Details:

• Excellent preservation and detail; natural and unrestored
• Ideal for academic study or high-end display collections
• Scale Reference: Each square or cube in the image = 1cm. See photo for accurate sizing

Authenticity & Guarantee: All of our fossils are 100% genuine, responsibly sourced, and come with a Certificate of Authenticity. The fossil you see in the photo is the exact one you will receive.

This rare Bigotites thevenini ammonite offers both aesthetic appeal and palaeontological significance. A must-have for collectors of European Jurassic cephalopods.