|Geology of the Mesozoic Era
Mesozoic Sea Level History of the United States
During the Mesozoic Era sea level played an important role in the evolution of the biotic world. Sea level was relatively low at the beginning of the Triassic. It rose periodically throughout the Triassic and Jurassic Period. However, during the Cretaceous Period sea level rose dramatically, and attained the highest level of the Phanerozoic. Some scientists believe that this high Cretaceous sea level is the result of the rapid expansion of oceanic crust coincident with the creations of the modern-day oceans.