Cretaceous Period Megalodon Megafauna Species Diversity Dinosaur Extinction Paleobiology Megalodon extinction Great White Shark Resurrection Great Apes Ichthyosaurs Conservation Species Interactions Human Impact Peirosaurids Prehistoric Life Pleistocene Mesozoic Era Woolly Mammoth Complex Life Forms Genyornis newtoni Ancient Organisms Woolly Mammoths Extinction Theories
Multi‑proxy isotopes from three North Dakota teeth point to riverine life enabled by a freshening Western Interior Seaway.