15.5" Cretaceous Rudist (Durania) Colony with Oysters - Kansas

This is a 15.5" wide cluster of fossil rudists of the species Durania maxima. They come from the Late Cretaceous Niobrara Formation (~83 million years) in Gove County, Kansas. There are a variety of other small marine bivalves scattered across this specimen. Specifically, a large gathering of Pseudoperna congesta oysters. Comes with a display stand.

A rudist is a ring-shaped marine heterodont bivalve that arose during the Late Jurassic and died out near the end of the Cretaceous. Durania maxima rudists had heavy cone shaped shells, often with a large, circular collar, and are typically found in the lower 1/3 of the Smoky Hill Chalk.

The Smoky Hill Chalk Member of the Niobrara Chalk formation is a Cretaceous conservation Lagerstätte, or fossil rich geological formation, known primarily for its exceptionally well-preserved marine reptiles. It outcrops in parts of northwest Kansas, its most famous localities for fossils, and in southeastern Nebraska. Large well-known fossils excavated from the Smoky Hill Chalk include marine reptiles such as plesiosaurs, large bony fish such as Xiphactinus, mosasaurs, pterosaurs, and turtles.
Durania maxima & Pseudoperna congesta
Gove County, Kansas
Niobrara Formation
15.5 x 9.5"
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