How much of North America did the inland sea cover during the Jurassic period?
The Cretaceous is actually the one that is generally referred to as the Inland Sea or Western Interior Seaway. But in the Jurassic, when sea levels rose, Alaska was the first land to disappear beneath the waters, and then Vancouver Island and much of California and Oregon. Later an inland sea covered most of British Columbia and much of Alberta, and extended over Montana, Idaho, Nevada, Utah and Wyoming, and a part of Colorado. This is the Logan Sea. In Wyoming, there are sedimentary rock layers more than 3,500 feet thick. Yes, there are fossils from the entire Mesozoic Era all over Canada, from British Columbia to Nova Scotia.
