RARE Fossil Heteromorph Ammonite Crioceratites thiollierei & Phyllopachyceras infundibulum – Cretaceous – Alice Purnell Collection

Description RARE HETEROMORPH FOSSIL AMMONITES – Crioceratites thiollierei & Phyllopachyceras infundibulum Lower Turonian, Cretaceous (~93.9 – 89.8 million years ago) Locality: France From the Alice Purnell Collection Includes Certificate of Authenticity This unique and scientifically valuable display fossil features two distinct and rare ammonite species: the heteromorph ammonite Crioceratites thiollierei and the planispiral Phyllopachyceras infundibulum. Both originate from the Lower Turonian stage of the Late Cretaceous, discovered in marine strata in France. This genuine fossil specimen is part of the Alice Purnell Collection, known for scientifically curated and accurately documented material. You will receive the exact fossil shown in the photos, with a 1cm scale cube provided for reference. See photos for full sizing. GEOLOGICAL & TAXONOMIC DETAILS: Age: Lower Turonian, ~93.9 – 89.8 million years ago Geological Period: Cretaceous Formation / Locality: Turonian marine sediments, France Depositional Environment: Epicontinental shallow marine environment with fine silts and carbonate-rich layers Biozone / Index Fossils: Early Turonian ammonite zones (potentially Watinoceras or related zonation) SPECIES 1: Crioceratites thiollierei Type: Heteromorph ammonite Family: Ancyloceratidae Superfamily: Ancyloceratoidea Order: Ammonitida Morphology: Open coiled, helicoidal to loosely spiraled form Notable Features: Lack of a compact spiral; highly irregular and evolute shell structure with prominent ribbing Scientific Relevance: Illustrates evolutionary experimentation in Cretaceous ammonite morphology. Heteromorphs like Crioceratites are often linked with deep-water or planktonic environments. SPECIES 2: Phyllopachyceras infundibulum Type: Planispiral ammonite Family: Phylloceratidae Superfamily: Phylloceratoidea Order: Ammonitida Morphology: Involute, thick-walled shell with distinctive lobed suture lines typical of the Phylloceratidae Preservation: Displays excellent ribbing and suture pattern detail, highlighting its phylogenetic placement Significance: This genus persisted from the Late Jurassic into the Late Cretaceous, often used for biostratigraphy DISPLAY & COLLECTOR VALUE: This paired fossil of heteromorph and planispiral ammonites is not only rare but also rich in comparative value for both academic study and private collectors. The contrasting forms—spiral and uncoiled—demonstrate the incredible adaptive diversity within the Ammonoidea clade during the Cretaceous seas. Fossils like these from the Lower Turonian of France are prized due to their well-preserved morphology, rarity, and relevance in understanding marine faunal turnover after the Cenomanian-Turonian boundary. INCLUDED WITH PURCHASE: Exact fossil shown in listing photos 1cm scale rule/cube for size reference Certificate of Authenticity Provenance from the Alice Purnell Collection Packaged securely and professionally for safe delivery This is a museum-quality ammonite fossil pairing ideal for display, research, or investment by collectors of marine fossils, heteromorph ammonites, or Cretaceous paleontology.