Rock Cycle - Past Life (2B)
Pre Lab 

  • Learning about the environments of the Mesozoic.
  • Comparing geologic time intervals.
  • Cenozoic
  • geologic time
  • Mesozoic
  • Paleozoic
  • worksheets
  • crayons
  • scissors

Students reconstruct the Mesozoic by making a diorama.

Nest of baby dinosaurs (dramatization)


Geologic time is divided into two eons; the Phanerozoic and PrePhanerozoic (or Precambrian). Phanerozoic means "visible life", which covers about the last 545 million years of earth history, are characterized by abundant visible fossils. The PrePhanerozoic Eon stretches from the formation of the earth, more than 4.5 billion years ago, until the start of the Phanerozoic. There are many fossils in PrePhanerozoic rocks, but they are microscopic. The Phanerozoic Eon is divided into three eras: the Paleozoic, Mesozoic, and Cenozoic.

The dinosaurs lived in the Mesozoic Era, which lasted about 180 million years, from about 230 million years ago until 65 million years ago. It is subdivided into three different periods: the Triassic Period, the Jurassic Period, and the Cretaceous Period. They appeared during the latter part of the Triassic Period (about 230 million years ago) and disappeared at the very end of the Cretaceous Period. During the 165 million years that dinosaurs existed, many changes took place on Earth. The continents shifted positions, the climate altered, and new types of plants and animals appeared.

Dinosaurs also changed both their appearances and geographic distributions along with Earth's Mesozoic environments. During the Triassic Period most of the continents were together, forming a single supercontinent called Pangaea. The climate was generally warmer than today's. At this time, there were few types of dinosaurs. Each type had a relatively large geographic distribution. As the Mesozoic progressed, Pangaea broke apart and the continents drifted away from each other. Dinosaurs thus could no longer travel between continents. Species on each continent lived and evolved in isolation from species on other continents. By the end of the Mesozoic, dinosaur diversity (the number of different types of dinosaurs) was greater, but the geographic range of each type of dinosaur was smaller than at the beginning of the Mesozoic.


In this exercise, the students will make a diorama that recreates a day in the life of a dinosaur. Use the following "cut outs" to help guide your students to create a diorama for each Mesozoic time period. Students may want to add other items like rocks, to make the diorama appear more realistic.

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