10" Fossil Mosasaur (Tylosaurus) Jaw Section - Kansas

This is a nicely preserved 10.0" mosasaur (Tylosaurus) jaw section from Gove County, Kansas. It contains the broken roots of six teeth and two unerupted teeth still deeply set in the sockets. It has three repaired cracks. This is the right dentary (lower jaw) bone.

Along with plesiosaurs, sharks, fish, and other genera of mosasaurs, Tylosaurus was a primary predator of the Western Interior Seaway during the Late Cretaceous. Among the largest of all the mosasaurs, Tylosaurus reached a maximum lengths of 14 meters (46 feet). A distinguishing characteristic is its elongated, cylindrical premaxilla (snout) from which it takes its name, and which may have been used to ram and stun prey and also for intraspecific combat. Tylosaurus was designated as one of two official Kansas state fossils in 2014.

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.
Gove County, Kansas
Niobrara Formation
We guarantee the authenticity of all of our
specimens. Read more about our
Authenticity Guarantee.