Rare Cranocephalites Fossil Ammonite, Jurassic, Lower Callovian, Waterpark UK, Genuine Specimen with COA

Description Offered here is a RARE Fossil Ammonite of the genus Cranocephalites from the Lower Callovian Stage of the Jurassic Period, discovered in the fossil-rich marine sediments of Waterpark, Ashton Keynes, Wiltshire, United Kingdom. This is a genuine and carefully chosen specimen, photographed to show the exact ammonite you will receive. Scale Rule Squares / Cube = 1cm — please refer to the photo for accurate sizing and detail. Key Geological and Scientific Information: Genus: Cranocephalites Fossil Type: Ammonite (extinct marine cephalopod) Geological Period: Jurassic Geological Stage: Lower Callovian (~164 million years ago) Location: Waterpark, Ashton Keynes, Wiltshire, England, UK Formation: Likely Kellaways Beds (marine silts and clays) Order: Ammonitida Superfamily: Stephanoceratoidea Family: Possible Kosmoceratidae or related group (subject to taxonomic placement) Described By: Genus originally described by Neumayr and Uhlig, 1892 Morphology Features: Cranocephalites is known for its narrow, compressed shell with well-defined, often sharp ribbing and a rounded to slightly keeled venter. Whorls are typically evolute to moderately involute, and the ribbing bifurcates from low on the flanks. The distinct shell structure makes it a recognizable and significant ammonite within Middle Jurassic assemblages. This specimen displays clear ribbing and preservation consistent with those traits, making it an excellent reference piece for the genus. Depositional Environment: This fossil likely originated from fine marine clays and silts within the Kellaways Beds, part of a low-energy, offshore shelf system that existed during the Callovian marine transgression. Such environments allowed delicate cephalopod shells to be buried rapidly and preserved intact. Stratigraphic Significance and Biozone (Tentative): Although not a global index fossil, Cranocephalites is frequently found in association with key Lower Callovian biozones, particularly in correlation with the Sigaloceras calloviense Zone and related ammonite faunal assemblages. Its stratigraphic position helps to support local and regional biostratigraphy in southern Britain and parts of Europe. Scientific Relevance: Cranocephalites holds paleontological value due to its distinct morphology and role in evolutionary lineages of Callovian ammonites. It contributes to the understanding of ammonite radiation and adaptation during a time of widespread marine transgression across the European Jurassic seaways. Authenticity Guarantee: All our fossils are 100% genuine specimens, professionally cleaned and prepared. Each purchase includes a Certificate of Authenticity, verifying species, provenance, and geological age. This Cranocephalites ammonite is an outstanding addition to any fossil collection, whether for academic study, display, or personal appreciation of Earth’s prehistoric marine life.