Arctoceras Zenoites Vikinghøgda Formation List of the Mesozoic life of Alaska List of the Mesozoic life of Nevada List of the prehistoric life of Nevada List of the Mesozoic life of Utah List of the prehistoric life of Alaska List of the prehistoric life of Utah List of ammonite genera List of the Mesozoic life of California List of the prehistoric life of California Olenekian List of things named after J. R. R. Tolkien and his works 2017 in paleomalacology 2018 in paleomalacology