Otosphinctes rudicosta Fossil Ammonite – Upper Oxfordian Jurassic – Deux Sevres France – Genuine with Certificate

Description This listing features a genuine Otosphinctes rudicosta Fossil Ammonite, discovered in the Deux Sèvres region of France, dating to the Upper Oxfordian stage of the Late Jurassic period. This specimen comes from the richly fossiliferous marine strata of the Oxfordian Formation, approximately 157 million years old. The photograph shows the exact specimen you will receive. Each scale square/cube equals 1cm for reference; please see full dimensions in the photo gallery. Otosphinctes is a genus of extinct ammonite molluscs that thrived in marine environments during the Late Jurassic. The species O. rudicosta is recognised for its distinctive ribbed ornamentation and compressed whorls, making it a favourite among collectors and palaeontologists alike. Scientific & Geological Details: Species: Otosphinctes rudicosta Genus: Otosphinctes Family: Perisphinctidae Super Family: Perisphinctoidea Order: Ammonitida Class: Cephalopoda Phylum: Mollusca Geological Age: Upper Oxfordian, Late Jurassic (~157 million years ago) Formation: Likely part of the Ampthill Clay or equivalent Oxfordian marine limestone Depositional Environment: Shallow marine shelf, warm epicontinental seas Morphological Features: Involute coiling Dense, bifurcating primary ribs with coarse ornamentation Narrow, compressed whorl section Biozone: May fall within the Bifurcatus or Transversarium zones of the Upper Oxfordian Formally Identified By: Species-level diagnosis attributed to detailed regional faunal studies of Oxfordian ammonites (historically documented by Arkell and others) Why This Fossil is Special: Otosphinctes rudicosta is not commonly found outside specialist collections. Its robust ribbing and excellent preservation from the Deux Sèvres locality make this an exceptional display or research specimen. Why Buy From Us? Every fossil is 100% genuine and comes with a Certificate of Authenticity You will receive the exact fossil pictured All specimens are professionally curated, cleaned, and documented Ethically sourced and legally obtained This fossil ammonite is ideal for serious fossil collectors, educational purposes, or as a one-of-a-kind natural history display piece. A window into the marine life of the ancient Jurassic seas of Western Europe.