LATE JURASSIC MORRISON FORMATION

The SunDance Sea extended through what is now western Canada into the central western United States starting in the Middle Jurassic advancing and withdrawing 5 times. The sea receded north for the last time when highlands to the west began to rise in the Late Jurassic. The Late Jurassic is divided into the Oxfordian, Kimmeridgian, Tithonian. The updated 022612

 
Hing Fat Allosaurus, UKRD CApatosaurus, Salvat Apatosaurus, Jasman Stegosaurus and Cog Dimetrodon

The Early Kimmeridgian: Windy Hill Member: The oldest member. At the time, the Morrison basin was characterized by shallow marine and tidal flat deposition along the southern shore of the Sundance Sea. The fauna is tranisitional with basal diplodocids Dystrophaeus and Eobrontosaurus. Haplocanthosaurus a primitive macronarian relative of the sucessful Camarasaurus. The medium sized basal sauropods may have lingered on in the North of the morrsion where it bordered the Artic Ocean. Allosaurus jimmadensi the first known of the allosaur species. Hesperosaurus is a primative stegosaur that broad round plates that seems related stegosaurs in Europe and China rather than the later Stegosaurus.

Wild Safari brachiosaurs CollectA Camptosaurus and Marshosaurus(Lourinhanosaurus), Wild Safari apatosaurs and allosaurs, UKRD Camarasaurus, CollectA dryosaurs(Hypsilophodon) and Safari Toob Champosaurus, Wild Safari Ceratosaurus and stegosaurs, Toyway Diplodocus and Wild Safari Allosaurus.

Middle Kimmeridgian: Tidwell Member: The Sundance Sea receded to Wyoming during this member and was replaced by lakes and mudflats. The Morrison fauna is established by this point. Giant sauropods, diplodocids and macronarians dominate the herbivores and Allosaurus is the most common predator. Turtles, crocodilians, fish and small mammals are diverse and numerous. This fauna remains largely the same for the rest of the Morrison’s history.