Rare 6″ Fossil Ammonite Proplanulites laevigatus | Jurassic Lower Callovian Kellaways Rock UK | Genuine COA

Description Offered here is a rare 6-inch fossil ammonite, Proplanulites laevigatus, dating to the Lower Callovian Stage of the Jurassic Period, discovered in the Kellaways Rock Formation at Semington Bypass, United Kingdom. The photo shows the actual specimen you will receive. Each square or cube in the photo equals 1cm — see the image for full size reference. This is a scientifically valuable and visually impressive fossil — perfect for display, academic study, or serious collectors of Jurassic ammonites. All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity. Geological & Scientific Information: Fossil Type: Ammonite Species: Proplanulites laevigatus Order: Ammonitida Superfamily: Stephanoceratoidea Family: Macrocephalitidae Geological Stage: Lower Callovian (~166.1 – 164.7 million years ago) Biozone: Lower Callovian Macrocephalites herveyi or Laevigatus Biozone (depending on zonal classification) Formation: Kellaways Rock (sandstone facies of the Kellaways Formation) Locality: Semington Bypass, Wiltshire, UK Depositional Environment: Shallow marine shelf; sandstones and siltstones deposited in a marginal marine to nearshore environment, often rich in molluscan fauna Morphology & Notable Features: Characterised by a smooth, compressed, and involute shell Whorl cross-section is oval to slightly depressed, with minimal ribbing or sculpturing The venter is smooth and narrowly rounded Umbilicus is small to moderately closed Sutures are simple and faint compared to more ornate ammonites, making the clean shell lines notable A classic example of streamlining and simplicity in Middle Jurassic ammonites Scientific Significance: Proplanulites laevigatus represents a transitional genus within Macrocephalitidae, often used in biostratigraphic zonation of Lower Callovian strata. The genus reflects a simplification trend in shell ornamentation during this time, making it particularly useful for understanding evolutionary and paleoenvironmental dynamics in Jurassic marine ecosystems. This species was formally described in the 19th century and has since remained an important marker ammonite for the lower Callovian of northwestern Europe. Ideal For: Advanced collectors of European Jurassic ammonites Biostratigraphers and geology students Museum and teaching collections Display fossil collections with a focus on classic British Jurassic material What You Will Receive: The exact 6″ Proplanulites laevigatus fossil ammonite pictured Certificate of Authenticity Professionally packaged for safe delivery worldwide