Recall when the supercontinent Pangaea existed.

The supercontinent Pangaea existed during the late Paleozoic and early Mesozoic eras, which was about 335 million to 175 million years ago. Here are the steps to recall when Pangaea existed:

1. Understand the concept of geological time: Geological time is a system of chronological dating that relates geological strata to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history.

2. Know about the Paleozoic Era: The Paleozoic Era is the earliest of three geologic eras of the Phanerozoic Eon, spanning from roughly 541 to 252.17 million years ago. It is the longest of the Phanerozoic eras and is subdivided into six geologic periods (from oldest to youngest): the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods.

3. Understand the Mesozoic Era: The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago. It is also called the Age of Reptiles and the Age of Conifers.

4. Learn about Pangaea: Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago and began to break apart about 175 million years ago.

5. Put it all together: So, to recall when Pangaea existed, you would need to remember that it was during the late Paleozoic and early Mesozoic eras, which was about 335 million to 175 million years ago.