Oistoceras Ammonite Fossil | Lower Lias, Jurassic Coast, Dorset UK | Green Ammonite Beds | Genuine British Fossil with Certificate

This is a genuine Oistoceras ammonite fossil from the Green Ammonite Beds of the Lower Lias Formation, collected from the iconic Jurassic Coast at Golden Cap, Seatown, Dorset, UK. This ammonite was discovered by our own team members Alister and Alison on 03 May 2025, and it has been expertly cleaned, prepped and treated by Alison to preserve its scientific integrity and aesthetic appeal. Fossil Overview: Species: Oistoceras sp. Fossil Type: Ammonite Location: Golden Cap, Seatown, Dorset, United Kingdom Stratigraphy: Green Ammonite Beds, Lower Lias Formation Geological Period: Early Jurassic (~190–195 million years ago) Stage: Upper Sinemurian Scale Reference: 1cm cube visible in photo Authenticity: Supplied with a Certificate of Authenticity Photo: What you see is exactly what you will receive Scientific Classification: Kingdom: Animalia Phylum: Mollusca Class: Cephalopoda Order: Ammonitida Superfamily: Eoderoceratoidea Family: Oxynoticeratidae Genus: Oistoceras Geological Stage: Upper Sinemurian (Early Jurassic) Formally Described By: Haug, 1887 Geological Context: The Lower Lias is part of the Blue Lias Group, famous for its fossil-rich marine sediments laid down during the Early Jurassic when this part of Britain was covered by a warm, shallow sea. The Green Ammonite Beds, specifically, are highly fossiliferous and are well-known among collectors and geologists for preserving a variety of ammonite species in exceptional detail. This ammonite was found in situ within the shale and limestone interbeds, characteristic of rhythmic sedimentation and low-oxygen sea floor conditions that helped preserve these animals in remarkable detail. Morphological Features: Typically involute shell with gently rounded whorls Fine, sinuous ribbing often seen extending across the flanks Distinct umbilicus and keel depending on preservation Oistoceras species are known for their delicate ribbing and flattened whorls, representative of the Oxynoticeratidae family Preservation in iron pyrite or limestone matrix is typical of the Green Ammonite Beds Notable Characteristics: From the UNESCO World Heritage Site Jurassic Coast Excellent teaching specimen or collector’s display A representation of Early Jurassic marine life and faunal turnover Offers scientific and aesthetic value with excellent natural preservation A classic example of Sinemurian ammonite evolution Summary: Genus: Oistoceras Age: ~190–195 million years old (Sinemurian Stage) Formation: Lower Lias, Green Ammonite Beds Location: Golden Cap, Seatown, Dorset, UK Collected By: Alister & Alison, 03 May 2025 Prepared By: Alison Certificate: Included with purchase Photo: Shows actual specimen Scale Cube: 1cm Note: All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity. The specimen has been carefully selected for its quality and rarity and is guaranteed to be the exact fossil you see in the photo. A perfect addition to any collection of Jurassic marine fossils.