Jurassic
Geologic period
The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago to the beginning of the Cretaceous Period, approximately 145 Mya. Wikipedia
Occurred: 201.3 (+/- 0.2) million years ago - 145 million years ago
Era: Mesozoic
Epochs: Early Jurassic, Middle Jurassic, and Late Jurassic
Chronological unit: Period
Lower boundary definition: First appearance of the ammonite Psiloceras spelae tirolicum
Lower boundary GSSP: Kuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria; 47°29′02″N 11°31′50″E / 47.4839°N 11.5306°E
Lower GSSP ratified: 2010