182.9 - 174.7 Ma

The definition of this interval in the timescale Ammonite Chrons of Northwest Europe is taken from the following source:

• J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 view

The bottom age has been interpolated based on the differences between the ages for international timescale boundaries quoted in the source and the currently accepted ages for those boundaries.

There are intervals in 6 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Toarcian age, Early Jurassic epoch
• Mesozoic Subages: Middle Toarcian subage, Late Toarcian subage
• Ammonite Chrons of Northwest Europe: Levesquei chron, Thouarsense chron, Bifrons chron
• Ammonite Chrons of North America: Kanense chron, Planulata chron, Carlottense chron, Hillebrandti chron, Crassicosta chron, Yakounensis chron, Arnioceras arnouldi chron
• Calcareous Nannoplankton Zones: NJ8 zone, NJ6 zone, NJ8a zone, NJ7 zone
• Permian-Jurassic of New Zealand: Temaikan age, Kawhia epoch, Ururoan age, Herangi epoch

This interval is used in the definition of 208 collections

A total of 3233 collections with 13666 occurrences lie within this time span