Perisphinctes Ammonite (Madagascar)

Perisphinctes is a genus of ammonites that lived during the Late Jurassic to the Early Cretaceous periods, approximately 160 to 120 million years ago. Characterized by their distinctive coiled shells with ornate ribbing and complex sutures, these cephalopods exhibit a wide range of morphological forms, reflecting their adaptation to various marine environments. Their shells typically display a planispiral shape, with some species showing distinctive whorls and tubercles. Perisphinctes ammonites were not only important index fossils, helping paleontologists date the rocks in which they are found, but they also played a crucial role in marine ecosystems as predators and prey. Their fossilized remains provide valuable insights into the biodiversity and evolutionary history of ammonites, as well as the ancient oceans they inhabited. The striking forms and intricate patterns of Perisphinctes make them a favorite among fossil collectors and a subject of study for researchers interested in paleobiology.