RARE 10″ Proplanulites Fossil Ammonite | Lower Callovian Jurassic | Manor Farm Wiltshire UK | Certified Genuine Specimen

Description An impressive and rare 10-inch fossil ammonite: Proplanulites sp., from the Lower Callovian Stage of the Middle Jurassic, collected from the renowned fossil-rich beds of Manor Farm, Wiltshire, United Kingdom. This exceptional example represents an important evolutionary stage in mid-Jurassic ammonite development, making it a desirable piece for collectors and educational display. The specimen shown is the exact fossil you will receive, photographed with a 1cm scale cube for size reference. Please refer to the images for detailed condition and dimensions.   Geological & Palaeontological Information: Fossil Type: Ammonite Genus: Proplanulites Geological Period: Jurassic Stage: Lower Callovian (~165 to 163 million years ago) Location: Manor Farm, Wiltshire, England, UK Depositional Environment: Shallow marine shelf; fine calcareous mudstones and silts from the Oxford Clay Formation Order: Ammonitida Superfamily: Stephanoceratoidea Family: Kosmoceratidae Biozone (Inferred): Likely within the Macrocephalites herveyi or Bullatimorphites bullatus Zones of the Lower Callovian, based on stratigraphy at Manor Farm   Morphological Features: Moderately involute shell with smooth or weakly ribbed flanks Broad, rounded whorls with a flattened venter in later growth stages Sutures typically complex, though less ornamented than later Kosmoceratid forms Potential faint keel or ventrolateral tubercles in some specimens   Notable Points: Proplanulites is considered transitional in form, marking key ammonite evolution in the Callovian Manor Farm is a scientifically significant site for Jurassic marine invertebrates Large, display-sized examples of Proplanulites are seldom available on the fossil market   Why This Fossil is Special: Rare ammonite genus from a globally important stratigraphic interval Excellent size and preservation from a UK heritage site Supplied with a Certificate of Authenticity 100% genuine and ethically sourced fossil Ideal for collectors, academic institutions, or interior display