Rare 4″ Grossouvria sulcifera Fossil Ammonite | Middle Callovian Jurassic | Ashton Keynes Wiltshire UK | Genuine Specimen with COA

Description This listing is for a Rare 4″ Fossil Ammonite (Grossouvria sulcifera) from the Middle Callovian Stage of the Middle Jurassic, discovered at Ashton Keynes, Wiltshire, United Kingdom. 100% Genuine Fossil Specimen – All of our fossils are authentic and come with a Certificate of Authenticity. Exact Specimen Shown – The photos provided are of the actual fossil you will receive. Scale for Reference – Scale rule squares/cube = 1cm. Please see photos for full sizing.   Geological & Scientific Details: Fossil Type: Ammonite (extinct marine mollusc, related to squid and octopus). Species: Grossouvria sulcifera. Order: Ammonitida. Superfamily: Stephanoceratoidea. Family: Tulitidae. Geological Period: Jurassic. Stage/Age: Middle Callovian (approx. 166 – 163 million years ago). Locality: Ashton Keynes, Wiltshire, UK.   Notable Features & Morphology: Shell Form: Moderately involute with robust, thick whorls. Ribs: Deep, widely spaced ribs crossing the flanks, giving the ammonite its characteristic “sulcifera” appearance. Whorl Section: Strongly rounded, producing a bold and striking shell. Size: A rare, large specimen at 4″, making it highly collectible.   Depositional Environment: During the Callovian, the Wiltshire area was covered by shallow marine seas depositing fine sediments and oolitic limestones. These conditions preserved ammonites and associated fauna in excellent detail.   Scientific & Collecting Importance: Grossouvria sulcifera is an important ammonite species for biostratigraphic correlation in the Callovian Stage. Its distinctive morphology and rarity make it both a scientifically valuable and highly desirable collector’s specimen.   Why Buy This Fossil? A rare ammonite species from the Middle Jurassic of Wiltshire, UK. Excellent preservation with bold ribbing and rounded whorl form. A significant addition for collectors of ammonites, Jurassic fossils, or UK material. Supplied with a Certificate of Authenticity guaranteeing its provenance.   All of our fossils are responsibly sourced, carefully prepared, and chosen for quality.