Jurassic

Definitions

The period from 201.3±0.2 to 145 million years ago, after the Triassic and before the Cretaceous; the geologic systems of this period.

Equivalents

Examples

“[p 108] Like⟳ the Forest Marble Beds in the Middle Jurassic, the Purbeck Beds of the Upper Jurassic are deltaic or estuarine in origin, so as well as mammals they contain⟳ small, presumably freshwater, crocodiles and the first indisputable lizards. [p 109] This is less surprising if it is recalled that in the Upper Jurassic, Europe and North America were joined to form⟳ Laurasia and the Atlantic Ocean still had to be formed …”

“Fossils are particularly well described from the Carboniferous, Triassic, Jurassic and Cretaceous periods and have⟳ been found in the USA, England, Russia, Lebanon and Germany. Sites such as Lyme Regis in Dorset have⟳ particularly yielded number⟳ of Jurassic “squid” ink sacs and nodules (Doguzhaeva et al. 2004).”

CEFR level