Under the uniformitarian dates assigned by secular geologists, it represents approximately the period of Earth's history from 200 million years ago to 145 million years ago.<ref>Gradstein, F.M., and Ogg, J.G.,[http://www.stratigraphy.org/scale04.pdf Geologic Time Scale 2004 – Why, How, and Where Next!]</ref> | Under the uniformitarian dates assigned by secular geologists, it represents approximately the period of Earth's history from 200 million years ago to 145 million years ago.<ref>Gradstein, F.M., and Ogg, J.G.,[http://www.stratigraphy.org/scale04.pdf Geologic Time Scale 2004 – Why, How, and Where Next!]</ref> |