Description This listing features a rare and well-preserved fossil of Dolikephalites dolius, a scientifically significant ammonite species from the Middle Callovian stage of the Jurassic period. The specimen originates from the fossiliferous marine beds of Madagascar, a region globally celebrated for its beautifully preserved Jurassic ammonite fauna. Geological Context: Fossil Type: Ammonite (Extinct marine mollusc, related to modern squid and octopus) Species: Dolikephalites dolius (Spath, 1928) Order: Ammonitida Superfamily: Stephanoceratoidea Family: Kosmoceratidae Geological Stage: Middle Callovian (c. 165.3 to 161.2 million years ago) Formation: Marine limestone and marl deposits of western Madagascar Depositional Environment: Shallow tropical marine shelf with carbonate-rich sediments Ammonites of the genus Dolikephalites are characterized by their moderately involute shells, complex suture patterns, and well-defined ribbing. These features make D. dolius a highly desirable specimen for both collectors and palaeontologists. Morphology & Notable Features: Planispiral shell with moderately compressed, slightly involute whorls Strong, bifurcating ribs extending across the flanks Rounded venter, occasionally with subtle tuberculation Prominent sutures typical of the Kosmoceratid lineage Rarely offered in the fossil trade, especially in complete condition Biozone Association: Dolikephalites dolius is most commonly associated with the Athleta Zone of the Middle Callovian, a key interval for biostratigraphic correlations in the Jurassic marine record of Madagascar and surrounding regions. Specimen Details: Origin: Madagascar Age: Middle Callovian Stage, Jurassic (~163 million years old) Scale: Scale rule square/cube = 1cm. Please see photo for exact dimensions Condition: Hand-selected for its preservation, clarity, and completeness Photo: The item you see is the exact fossil you will receive Certification & Authenticity: All of our fossils are 100% genuine and come with a Certificate of Authenticity. Each specimen is professionally reviewed and chosen for its scientific value and display quality. This rare Dolikephalites dolius ammonite is a striking and valuable addition to any fossil collection, bringing a fascinating piece of Jurassic marine history from the ancient seas of Madagascar into your hands.
