fossilera:A new premium fossil listing at FossilEra.com Nine articulated and fused vertebrae of a M
fossilera:A new premium fossil listing at FossilEra.com Nine articulated and fused vertebrae of a Mosasaur, Platycarpus tympaniticus. This specimen was collected from the Late Cretaceous, Niobrara Chalk Formation of Kansas. This 20 inch long section of the vertebral column to this monstrous prehistoric reptile has been mounted on a custom metal stand creating a very aesthetic display. The Niobrara Chalk was was laid down in the Late Cretaceous, when the middle to the United States was covered by the Western Interior Seaway. It underlies much of the Great Plains of the US and Canada. Evidence of vertebrate life is common throughout the formation and includes specimens of plesiosaurs, mosasaurs, and pterosaurs as well as several primitive aquatic birds. -- source link