RARE: Hoploscaphites nicoletti Fossil Ammonite – Maastrichtian, Cretaceous – Pierre Shale – South Dakota, USA – Alice Purnell Collection

Description RARE FOSSIL AMMONITE – HOPLOSCAPHITES NICOLETTI – MAASTRICHTIAN STAGE, UPPER CRETACEOUS – PIERRE SHALE FORMATION, SOUTH DAKOTA, USA This is a stunning and rare specimen of the heteromorph ammonite Hoploscaphites nicoletti, collected from the world-famous Pierre Shale Formation in South Dakota, USA. This specimen dates to the Maastrichtian stage of the Late Cretaceous period, approximately 70–66 million years ago, making it one of the last ammonites to exist before the K-Pg extinction event. This fossil comes from the Alice Purnell Collection, renowned for its careful curation and scientifically significant specimens. The fossil you see in the listing photograph is the exact one you will receive, and it includes a scale cube (1cm squares) for accurate reference. Every fossil includes a Certificate of Authenticity and is guaranteed 100% genuine. GEOLOGICAL & TAXONOMIC INFORMATION: Species: Hoploscaphites nicoletti Genus: Hoploscaphites Geological Period: Late Cretaceous Stage: Maastrichtian Formation: Pierre Shale Location: South Dakota, USA Depositional Environment: Offshore marine shelf, fine silty-clay sedimentation, anoxic to dysoxic seabed conditions Biozone: Upper Maastrichtian ammonite zone (Hoploscaphites nicolletii zone) Family: Scaphitidae Superfamily: Scaphitoidea Order: Ammonitida Class: Cephalopoda Phylum: Mollusca Identified by: Species originally described by Meek in 1876 MORPHOLOGICAL FEATURES: Hoploscaphites nicoletti is a classic example of a heteromorph ammonite, displaying a partially uncoiled shell that tightly coils in the early stages and later curves outward. This feature is thought to be an adaptation to a nektobenthic lifestyle, possibly involving vertical movement through the water column. It is characterised by: An involute inner whorl followed by an uncoiled body chamber Strong ribbing and possible tubercles Rounded venter with occasional keels Well-defined sutures These features provide important data on evolutionary patterns in Late Cretaceous marine faunas. NOTABLE ASPECTS: From the terminal Cretaceous before the mass extinction event Sourced from Pierre Shale, a globally significant fossil-bearing formation Excellent preservation showing diagnostic morphology Ideal for scientific study or premium fossil display From the prestigious Alice Purnell Collection Comes with a Certificate of Authenticity SUMMARY: Species: Hoploscaphites nicoletti Age: Maastrichtian Stage, Late Cretaceous (~70–66 Ma) Locality: Pierre Shale, South Dakota, USA Preservation: Distinct heteromorph structure, visible ribbing Collection: Alice Purnell Authenticity: 100% genuine, certified fossil Photo: Actual specimen shown – 1cm cube for size reference This Hoploscaphites nicoletti specimen is not only an excellent fossil for collectors but also holds palaeontological value as one of the last ammonite species before extinction. A perfect addition to any serious collection or educational display.