Solve a Sedimentary Layers Puzzle

SOLVE A SEDIMENTARY LAYERS PUZZLE

Did you know that the 1. Photocopy and cut out the ﬁ ve strips of paper history of life on Earth Each strip represents a sedimentary rock layer formed during a certain time period. is told through rocks? Dinosaur fossils Over millions of years, sediments 2. Put the layers in correct order have been such as sand and silt were laid FUN discovered on Begin by placing B, the “oldest layer,” FACT down and compressed to form on the bottom. Then decide which every continent, sedimentary rock layers. They layer comes next. It will have some even Antarctica. preserve a record of ancient land- of the same organisms as the older scapes, climates, and organisms. layer and some new ones. (Hint: Organisms do not disappear for a layer and then reappear.) Place it above. Continue until the layers are in order, Scientists often determine the with the youngest at the top. Check your answers and write the time correct sequence of sedimentary period on each layer. rock layers using the fossils found within them. They compare the Explore More! fossils to ﬁ gure out if two layers Look at the fossils within each layer. What plants and animals lived are from the same geologic time during the same time period? Then compare the layers to explore the period, or if one layer is older changing plant and animal groups throughout Earth’s history. Which than the other. organisms survived from one time period to the next? Which ones went extinct? Could Tarbosaurus have hunted Seismosaurus? What organ- Try reconstructing the layers isms survived the mass extinction at the end of the Cretaceous Period? below using the same strategy!

gingko sharks birds dyrosaurs horses dragonﬂ y ﬂ owering A plants

Coelophysis gingko pterosaur Efﬁ gia dragonﬂ y sharks ammonites icthyosaurs B Postosuchus OLDEST LAYER

gingko birds dragonﬂ y sharks ammonites ﬂ owering Tarbosaurus dyrosaurs plants pterosaur C icthyosaurs bataar

Homo sapiens gingko birds dragonﬂ y ﬂ owering horses D sharks plants

gingko ammonites birds pterosaur Seismosaurus Stegosaurus

E dragonﬂ y sharks icthyosaurs

C (Cretaceous Period, 145-65 mya), E (Jurassic Period, 200-145 mya), and B (Triassic Period, 250-200 mya) 250-200 Period, (Triassic B and mya), 200-145 Period, (Jurassic E mya), 145-65 Period, (Cretaceous C

Order of layers from top to bottom: D (Quaternary Period, 2 million years ago to present), A (Tertiary Period, 65-2 mya), mya), 65-2 Period, (Tertiary A present), to ago years million 2 Period, (Quaternary D bottom: to top from layers of Order Answers: