Fossil Ammonite – Cardioceras persecans – Oxfordian, Jurassic – Zalas, Poland – Genuine Specimen with Certificate

Description Fossil Ammonite – Cardioceras persecans Geological Period: Jurassic Stage: Oxfordian (~163–157 million years ago) Locality: Zalas, Lesser Poland Voivodeship, Poland All of our Fossils are 100% Genuine Specimens & come with a Certificate of Authenticity This listing features a beautifully preserved fossil ammonite of the species Cardioceras persecans, a diagnostic and classic representative of the Oxfordian marine fauna of the Jurassic period. It was discovered at Zalas, a historically important locality for Upper Jurassic ammonites in Poland, well-known for its finely bedded marl and limestone layers rich in cephalopods. Taxonomy & Scientific Context: Genus: Cardioceras Species: persecans Family: Cardioceratidae Superfamily: Stephanoceratoidea Order: Ammonitida Formally Identified by: Arkell (based on morphological comparisons and Oxfordian zonation) Morphology & Notable Features: Cardioceras persecans is characterised by its typically discoidal shell with a relatively open umbilicus and strong, bifurcating ribs that cross the venter cleanly. The whorl section tends to be compressed, and the ornamentation is particularly prominent, often forming sharp ridges and nodes—making specimens such as this highly sought after by collectors. This genus is well-known for its short stratigraphic range, making it a key biostratigraphic indicator in the Upper Jurassic ammonite zonation. Geological & Environmental Information: Zone/Biozone: Cardioceras cordatum to Cardioceras densiplicatum zones (Oxfordian ammonite zonation) Depositional Environment: Shallow marine epicontinental shelf conditions. The Zalas region in Poland preserves marine sediments indicative of a warm, subtropical sea with fluctuating oxygen levels and diverse invertebrate fauna. Stratigraphy: Oxfordian marl-limestone alternations with distinct cephalopod-rich beds. Preservation Quality: Excellent, with clear suture lines and prominent ribbing visible across the shell. Ideal for both study and display. Specimen Display & Size: The actual fossil shown in the photos is the one you will receive. Scale Rule Squares / Cube = 1cm – please see photos for full sizing. Ideal For: Collectors of Jurassic ammonites Palaeontology educators Students studying European marine biostratigraphy Fossil lovers looking for visually striking specimens from classic localities This is a standout piece and a fantastic representative of the Oxfordian ammonite fauna from Central Europe.