Late Jurassic

The Late Jurassic is the third epoch of the Jurassic period, and it lasted from about 161.5 to 143.1 million years ago. This time is very important for scientists who study Earth’s history. They study rocks called Upper Jurassic strata to learn about plants, animals, and the environment from long ago.

In Europe, rocks from this time are often called "Malm" in a special way of studying rocks called lithostratigraphy. Scientists now use the word Malm only for the rocks, not for the time period. This helps them keep rocks and time separate. The Late Jurassic was when many famous dinosaurs lived, and the continents looked very different from today.

Subdivisions

The Late Jurassic is divided into three ages. These ages match the three faunal stages in Upper Jurassic rock layers. They help scientists learn about events and changes from millions of years ago.

Paleogeography

By the Late Jurassic, the huge landmass called Pangaea had split into two main parts: Laurasia in the north and Gondwana in the south. Laurasia included places like Eurasia and North America. Gondwana included Africa, South America, Arabia, Antarctica, Australia, India, and Madagascar. New, narrow oceans formed between these landmasses. These included the early Atlantic Ocean and the Tethys Ocean. The oceans brought more moisture to areas that were once very dry.

Climate

During the Late Jurassic, deep oceans covered the poles. This stopped polar ice caps from forming, so polar summers had no ice. Ocean currents moved between different areas, helping to keep the climate warmer than today. Over time, Europe became drier and more arid.

Life forms

This time period is famous for many well-known dinosaurs. These included big sauropods, meat-eating theropods, armored thyreophorans, and plant-eating ornithopods. Other animals also lived during the Jurassic, such as crocodylomorphs and the first ever birds. The Late Jurassic had many different kinds of creatures, and even more animals existed than these examples.