About 100 million years ago, the land pictured here was once part of a sandy area very near the shores of a great inland sea called the Western Interior Seaway. The seaway spanned the region we now call North America from the middle of present day Utah across to the Appalachian Mountains to the east. It was teaming with life including giant marine reptiles such as plesiosaurs and sharks too. There were also birds that had just come on to the evolutionary scene, so early in fact that many species still sported teeth.