Chrysomallus

Chrysomallus is a genus of extinct marine gastropods belonging to the family Pleurotomariidae. These prehistoric snails lived during the Triassic period, approximately 252 to 201 million years ago. Fossils of Chrysomallus have been found in various parts of the world, indicating a widespread distribution during their existence. The defining characteristic of Chrysomallus, like other pleurotomariids, is the presence of a slit or fissure on the outer lip of their shell, known as a selenizone. This feature served a respiratory function, allowing water to pass over the gills. The shell itself is typically coiled and conical, with a prominent apex and a series of spiral ribs or cords. The exact ecological role of Chrysomallus is not fully understood, but it is believed to have inhabited shallow marine environments, feeding on algae or detritus on the seafloor. The genus became extinct by the end of the Triassic, likely succumbing to the mass extinction event that marked the transition to the Jurassic period. Its fossil record provides valuable insights into the marine life and evolutionary history of the Paleozoic and Mesozoic eras.