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 period is very important for scientists who study Earth’s history because it is preserved in rocks known as Upper Jurassic strata. By looking at these rocks, scientists can learn about the plants, animals, and environment from long ago.

In Europe, rocks from the Late Jurassic are often called "Malm" in a special way of studying rocks called lithostratigraphy. While people used to use the word Malm to talk about the time period itself, scientists now avoid doing this. This helps make a clear difference between talking about the actual rocks and talking about the time they were formed. The Late Jurassic was a time when many famous dinosaurs lived and the continents were arranged very differently than they are today.

Subdivisions

The Late Jurassic is split into three ages, matching the three faunal stages found in Upper Jurassic rock layers. These ages help scientists understand the order of events and changes that happened millions of years ago during this time.

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, while Gondwana included Africa, South America, Arabia, Antarctica, Australia, India, and Madagascar. New, narrow oceans formed between these landmasses, including the early Atlantic Ocean and the Tethys Ocean. These oceans brought more moisture to areas that were once very dry.

Climate

During the Late Jurassic, deep ocean basins covered the poles, which prevented the formation of polar ice caps. This meant that polar summers were free of ice. The movement of ocean currents between different latitudes helped keep the climate warmer than it is today. Over time, Europe became drier and more arid during this period.

Life forms

This time period is famous for many well-known dinosaurs, including the large sauropods, meat-eating theropods, armored thyreophorans, and plant-eating ornithopods. Besides dinosaurs, other animals lived during the Jurassic, such as some crocodylomorphs and the first ever birds. The Late Jurassic had a rich variety of creatures, and many more animals existed beyond these examples.