Earth and Space Sciences Fossils: When dinosaurs took to the skies Earth scientists use rocks and fossils to obtain clues about the environment that existed many millions of years ago. Just recently, some scientists made a discovery about a four-winged feathered dino-bird! In this lesson you will investigate the following: • What are the different classes of rocks? • Why do earth scientists use the geological time scale? • How are fossils made? • What was it like to live with dinosaurs? It’s time to spread your wings and soar back into the distant past! This is a print version of an interactive online lesson. To sign up for the real thing or for curriculum details about the lesson go to www.cosmosforschools.com Introduction: Fossils The closest living relation to the dinosaurs could be your budgerigar! We’ve long known that birds evolved from dinosaurs, but a new discovery – the fossil of a feathered flying dinosaur in rocks in a remote part of China – tells us more than we have ever known about how dinosaurs and early birds took to the skies. The newly discovered dinosaur is called Changyuraptor yangi. It was the size of a large eagle, weighing roughly 4 kilograms and measuring about 1.3 metres from snout to tail. And it had not two, but four wings and a long plumed tail. So well preserved were the feathers of the flying dinosaur's tail that scientists could work out how it was used in flight. They believe that it allowed the dinosaurs to adjust their pitch – that is, whether they were flying nose up or nose down – as well as to slow their speed and help them land safely. The discovery adds to the growing body of evidence that the late Jurassic and early Cretaceous periods were important for the evolution of feathered flight. As one scientist says, “There were lots of different lineages experimenting with modes of flight at this time. The lineage that became modern birds was just one of them.” Read or listen to the full Cosmos magazine article here. Left: Archaeologists use delicate tools to uncover long-buried fossils. Here, archaeologist Eric Buffetaut can be seen excavating the neck of a Sauropoda dinosaur. Right: The skeleton of an Argentinosaurus huinculensis, the world's largest herbivore, is displayed at the Lokschuppen exhibition centre in Rosenheim, Germany. Credits: Patrick Aventurier / Gamma-Rapho via Getty Images and Luka Barth / epa / Corbis. Question 1 Imagine: You are a palaeontologist working at a university and have been contacted by a farmer who has stumbled across a strange looking fossil. Describe how you might feel if you visited the farmer and then spent one month digging up one of the largest dinosaurs ever found (Argentinosaurus, 36 m from tail tip to nose). Gather: Fossils Loading... Credit: Untamed Science / YouTube. Question 1 Remember: What are the three classes of rocks? Question 2 Define: Igneous rocks are composed of different minerals that form as magma (molten rock) cools and solidifies. The slower the magma cools, the larger the crystals formed. Which of the two igneous rocks below is a granite (that cools deep in the Earth very slowly) and which is a basalt (that cools very quickly when the magma reaches the surface of the Earth)? Give a reason for your answer. Two types of igneous rock. Credits: James Driscoll and Thomas Weiland Question 3 Question 4 Identify: Sedimentary rocks are formed: Recall: Sedimentary rocks can be formed by eroded sediments of other sedimentary rocks, igneous rocks and/or metamorphic by weathering and eroding other rocks rocks. under the oceans True in rivers and streams False any of the above Question 5 Identify: Which class of rock is represented by the photograph on the right and how do you know this? Hint: what has caused the layers in the rock to be deformed? Credit: iStock. The rock cycle is a similar concept to the water cycle you studied in Year 7. As we saw from the video there are three main classes of rock: sedimentary, metamorphic, and igneous, and the differences between them have to do with how they are formed. Rocks are not always as static and solid as they appear. They are constantly changing over timescales from a few minutes (in the case of lava flowing out of a volcano in Hawaii) to many millions of years (in the case of the Himalaya mountains in southern Asia being uplifted and folded). To start the rock cycle, hot molten rock from the Earth's mantle, also called magma, reaches the surface of the Earth and erupts from volcanoes as lava. The lava cools and forms igneous rocks. Weathering by wind, ice and rain results in the rocks being eroded, broken up and transported along rivers and streams into the ocean. The particles of sand, shells and pebbles, which are collectively called sediment, slowly build up over hundreds of thousands to millions of years. They are compressed, and sedimentary rocks form. Sedimentary rock is the most common type of rock on Earth. As more and more sediment accumulates increased pressure and temperature leads to deep sedimentary rocks slowly transforming into metamorphic rocks. Over millions of years the temperature of the Earth may melt some metamorphic rocks back into magma. And so the process continues. Question 6 Identify: Use Google Earth to locate an area that is local to your school where sediment being deposited may form sedimentary rock in the future. Upload a snapshot of the area Annotate where the sediment is being eroded from (Hint: The sketchpad can be used to annotate images) Describe how the sediment is being transported to the depositional area Process: Fossils Left: Dinosaur in the Jurassic Museum of Asturias. Right: Fossil crinoids (Uintacrinus socialis) from the Cretaceous Period (145.5 – 65.5 million years ago). Credit: Javier Prieto Gallego / Cover / Getty Images and iStock. Simple cells represent the earliest life forms on Earth. They first appeared approximately 3.6 billion years ago. More complex life forms evolved only approximately 600 million years ago. When these ancient plants and animals died their remains were sometimes preserved as fossils in sedimentary rock. Fossils are much more common than you may think since so many animals and plants live and die and because sedimentary rocks are so common. Dinosaurs are arguably the most fascinating and well-known fossils. Flying dinosaurs such as Changyuraptor and Archaeopteryx represent transition animals that existed between dinosaurs and birds. Earth scientists and geologists who study fossils and ancient life are known as palaeontologists. Loading... Credit: SheppardSoftwareCom / YouTube. Question 1 Classify: Which type of animal might have left the trace fossil tracks depicted below right? On paper, draw a sketch of what the animal may have looked like and upload a photograph or scan of your sketch. Hint: The animal that left these tracks may have been being swooped by an Archaeopteryx, depicted soaring overhead (below left). Drag and drop file here to begin upload or Credit: Corey Ford / Stocktrek Images / Getty Images and Tom Bean / Corbis. Question 2 Think: How are resin fossils formed? List three animals that may become resin fossils. Question 3 Paraphrase: On very rare occasions exceptionally well-preserved body fossils have been discovered. Use the information in the video clip above to explain how dinosaur body fossils can be preserved in rock. Earth scientists and geologists use the geological timescale, also known as a stratigraphic chart, to measure Earth's history over millions of years. Geological time is divided into eras, periods, epochs and stages with each division based on a specific set of geological or palaeontological conditions that make it different from the other divisions, such as varying rock type or fossils. Time is measured in millions of years (sometimes written as "Ma"). Today we are living during the Holocene Epoch of the Quaternary Period. Using the chart, we could assign a sedimentary rock that has fossils dating to 105 Ma (105 million years old) as belonging to the Albian Stage of the Lower Cretaceous Epoch of the Mesozoic Era. Explore this stratigraphic chart before continuing. Question 4 Apply: A sedimentary rock contains this flying insect fossil that has been dated to 309 Ma. Using the geological time scale, classify the age of the rock into Stage, Period and Era. Credit: iStock. Question 5 Infer: The Cosmos article suggests that flying dinosaurs first appeared at the beginning of the Upper Jurassic, and were extinct by the end of the Lower Cretaceous. 1. Calculate how many millions of years the flying dinosaurs dotted the skies of the Earth. 2. Calculate the percentage of time in Earth's history this represents based on the Earth being 4.6 billion years old. Question 6 Imagine: You're an old flying dinosaur from the Upper Jurrasic and feel that your death is imminent! But you are a smart dinosaur that knows about fossilisation and want to make sure that your body is preserved for future discovery by humans. In the first person, write a narrative of about 200 words to describe the long journey from your last day on Earth to your fossil being discovered by humans millions of years later. Be creative in your writing! Apply: Fossils Exploring your backyard Sedimentary rocks can reveal secrets from the past (like the shells above left) and create stunning scenery (like "The Wave" in northern Arizona, above right). Credit: iStock. Time to choose! There are two tasks below and you may complete either one (or both!). The first task is a hands-on activity, while the second you can complete from the comfort of your computer screen.