Activity 7: Fossil Tracks
Creating and analyzing tracks by students allows them to participate like a paleontologist in real track way analysis.
Instructional Method: Game
Objectives: Students will be able to:
Setup: 60 min
For a long time paleontologists found tracks of dinosaurs, crocodiles, mammals, worms and other past life forms preserved in mud and dirt as trace fossils. Many scientists viewed these fossils as insignificant because of the difficulty in distinguishing who made the fossil track.
Today scientists are able to distinguish between tracks made by amphibians, reptiles, birds and mammals. They can even figure out who made a particular track to the level of order, family and sometimes genus. Many modern paleontologists are now using tracks to learn more about animal behavior, ecology (interactions between living and non living things) and the diversity of ancient environments.
Being able to make these identifications is many times a process of elimination. For instance if a huge three toed track was found in the late Cretaceous it would be easy to say that it was probably made by a Tyrannosaurus. If the footprint was made in the late Jurassic we would determine it was made by an Allosaurus, because Tyrannosaurs did not live in the Jurassic.
Track ways provide valuable information about animal behavior and diversity. When track ways are found with numerous sets of the same shaped tracks with many different sizes, all headed in the same direction, scientists are able to determine that the animals traveled in herds with parents and juveniles. If you find in track ways only one set of an individual shape you know that the animal lived a relatively solitary life following a migratory path for food.
Finding a variety of different animal prints suggests diversity. You can determine which animals lived in coexistence and in what type of environments by observing their footprints. The flying dinosaurs, Pterosaurs, are known to live near tidal flats. Scientists discovered this after finding pterosaur tracks only in tidal flat deposits.
By taking measurements of the distance between footprints, the size and speed of a dinosaur can be estimated. More on dinosaur speed can be found in the extension exercises. They can tell us if the animal walked like a crocodile or with its legs underneath them like a horse. If tracks are random or a limb is dragged we know the animal was injured.
The following activity allows students to make dinosaur tracks following different scenarios and then allow them time to find out how much information they can gather from the tracks.
How many dinosaurs are represented on the paper? What kinds are represented? Are they all the same age? Height? Weight? Shape? Color? Speed? What was happening when the footprints were made? How do students know what was happening? Can they tell what the animals ate? Where they lived? How did the animals defend themselves? Did they need to defend themselves?
Instead of using paint and paper to act out the scenarios, you can use large smooth cement surfaces and runny, clayey mud. If you prefer not to act out the activities, you can print out PDF form sheets with tracks already on them and have students decipher the information presented.
This is a fun exercise that encourages mathematic use in paleontology. After the new track ways have dried, take a few rulers and measure the distance between tracks. When measuring distances measure from toe to toe or heel to heel on either the right foot only or left foot only. This is the stride length. Also measure the length of a foot print. To figure a dinosaurs speed by tracks you need its hip height. Finding a dinosaur's hip height = 4 x the foot print length. A dinosaur's speed = stride / hip height. You can tell how fast a dinosaur was moving by the following list: 0-2 = walking, 2-2.9 = lope, >2.9 = running. Work sheet provided in PDF form.
Included National Parks and other sites:
Agate Fossil Beds National Monument
Utah Science Core:
4th Grade Standard 4 Objective 1,2