Pangaea believed to be the main cause of the shrinking of lysocline areas. The third cause of this extinction event that can be attributed to northern Pangaea is the beginnings of anoxic ocean environments, or oceans with very low oxygen concentrations. The mix of anoxic oceans and ocean acidification due to metal loading led to increasingly acidic oceans, which ultimately led to the extinction of benthic species. Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago, and it began to break
Geology of Saskatchewan and marine life. The Williston basin was formed creating a lowered land area during this period filling with the Winnipeg Sea. The Williston basin was mainly south of Saskatchewan but extended north into the Saskatchewan plains area. Laurasia was created near the end of the Silurian Period. Laurasia was formed from the joining of Laurentia with Gondwana and two smaller continents which had broken off Rodinia. The orogeny between Laurasia and Gondwana created the Appalachian Mountains, and an exodus of water from the Laurasian land surface. In the early Devonian Period 418-361 Ma, Laurasia separated from Gondwana, creating a depressions