Complex sentence: The geological history of Point Lobos started around 100 million years ago during the Cretaceous Period, when the dinosaurs still roamed the earth and pterodactyls dominated the sky.
Split into simpler sentences: The geological history of Point Lobos encompasses the last 100 million years. The oldest rocks exposed here were formed during the Cretaceous Period, when the dinosaurs still roamed the earth and pterodactyls dominated the sky.