Chronostra-what? The long word may be new to you, but you’ll find the concept familiar. Case in point: Jurassic Park. You can thank chronostratigraphy for the name, even though any dino nerd will tell you it should have been called Cretaceous Park. That’s because most of the animals in the park, including T. rex, lived around the end of the Cretaceous, tens of millions of years after the Jurassic. How do paleontologists know that? Thank chronostratigraphy for that one, too.
During 18th-century mining explorations and early 19th-century fossil digs, expeditioners noticed similarities in rocks over large geographic areas. And so stratigraphy — the study of layers (strata) of rock in relation to each other — was born. Chronostratigraphy is a modern offshoot of this discipline, organizing these dateable rock layers into chronological units. The standardized system gives geologists, paleontologists, and researchers from many other fields a framework of how our planet, and life on it, has changed over time.
