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  1. 1. Dinosaur Footprints and Trackways I.G. Kenyon
  2. 2. Dinosaur trackways, Tuba City, Arizona, USA
  3. 3. Measuring Dinosaur Footprint Length Measure the straight line distance from the tip of the longest toe to the back of the foot
  4. 4. Usefulness of Footprint Length Hip Height or Leg Length is equal to 4 X the Footprint Length
  5. 5. Usefulness of Footprint Length Animal length from nose to tail is equal to 10 x the Footprint length
  6. 6. Measuringing Stride Length Stride length is the distance between successive prints of the same foot.
  7. 7. Stride Length ÷ Hip Height Relative Speed Less than 2.0 Walking Between 2.0 and 2.9 Trotting Greater than 2.9 Running
  8. 8. Ultrasaurus Footprint Length = 3.1 metres long Calculate its hip height and total length from head to tail
  9. 9. Ultrasaurus Hip height = 3.1 x 4 = 12.4 metres Length from head to tail = 3.1 x 10 = 31.0 metres
  10. 10. Compsognathus One of the smallest dinosaurs 76 cm from head to tail when fully grown. What would be the length of its footprint?
  11. 11. Compsognathus Footprint length = 76 ÷ 10 = 7.6 centimetres
  12. 12. Microceratops Microceratops measured just 76 cm in length. It had a hip height of 30 cm and a stride length of 46 cm. Was it walking, running or trotting?
  13. 13. Microceratops Stride Length 46 cm ÷ Hip Height 30 cm = 1.53 As this value is less than 2.0, it was walking.
  14. 14. Velociraptor Velociraptor footprints are typically 18 cm long. What is the hip height of the animal? Stride length in a trackway is 250 cm. Was Velociraptor walking, trotting or running?
  15. 15. Velociraptor Hip height = 18 cm x 4 =72 cm Stride length 250 cm ÷ Hip height 72cm = 3.47 Value is over 2.9, therefore it was running.
  16. 16. Acrocanthosaurus Footprints measure 51 cm in length. What was the head to tail length of the animal? What other measurement is needed to find out how fast it was moving?
  17. 17. Acrocanthosaurus Length of animal 51 cm x 10 = 5.1 metres Need to know the stride length to calculate speed and type of movement
  18. 18. Gallimimus Could reach running speeds of 35 mph Value for its Stride length ÷ Hip height likely to be? If slowed to a walk would stride length be shorter/longer?
  19. 19. Gallimimus Stride length ÷ Hip height value would be greater than 2.9 If it slowed to a walk, then stride length would be shorter
  20. 20. Calculating how fast Dinosaurs Moved 1 Measurements Required: Footprint Length (Measured from Trackway) Leg Length (Hip Height) = 4 x Footprint Length Stride Length (Measured from Trackway) Relative Stride Length = Stride Length ÷ Leg Length
  21. 21. Calculating how fast Dinosaurs Moved 2 Dimensionless Speed is based on the fact that upright tetrapods (humans are bipedal tetrapods) regardless of size move in the same way. Dimensionless Speed (DS) = (Relative Stride Length-1) ÷ 1.1 Relative Stride Length (RSL) = 1.1 x DS + 1
  22. 22. Calculating how fast Dinosaurs Moved 3 Alexander’s Equation For calculating the speed of dinosaurs: Speed = √ (Leg Length x g) x DS G = 9.8 m/s
  23. 23. Complete the Table below using the formulae given on the previous slides Dinosaur Foot Length (m) Stride Length (m) Leg Length (m) Relative Stride Length Dimensionless Speed Actual Speed (m/s) Actual Speed (km/h) Hadrosaur 0.3 1.4 Struthiomimus 0.23 1.2 Velociraptor 0.25 1.34 Euoplocephalus 0.40 2.72 Stegasaurus 0.35 1.87
  24. 24. Dinosaur Foot Length (m) Stride Length (m) Leg Length (m) Relative Stride Length Dimensionless Speed Actual Speed (m/s) Actual Speed (km/h) Hadrosaur 0.3 1.4 1.2 1.17 0.15 0.51 1.84 Struthiomimus 0.23 1.2 0.92 1.46 0.42 1.26 4.54 Velociraptor 0.25 1.34 1.00 2.72 1.56 4.88 17.57 Euoplocephalus 0.40 2.72 1.60 1.17 0.15 0.59 2.12 Stegasaurus 0.35 1.87 1.4 1.36 0.33 1.22 4.39 Answers
  25. 25. Sauropodamorphs up to 5 (walking speed of people) Stegosaurs and Ankylosaurs walked 6-8 Sauropods walked 12-17, with max of 20-30 Large Theropods (T. rex) and Ornithopods to 20 Ceratopsians 25, Small Theropods, Ornithopods 40 Ornithomimids up to 60 Humans run up to 23 (fast sprinting speed) Using Alexander's equations, the follow speeds (km/h) were calculated by R. A. Thulborn (1982, Australian)
  26. 26. 100 Ma this area was a mudflat on the edge of a lake
  27. 27. What do you think the footprints shown in Map 1 tell you about the two dinosaurs? What happened to the 2 dinosaurs where the ground is hidden by the buildings in the east? What evidence in support of your ideas would you expect to see when more of the footprints have been uncovered?
  28. 28. Suggested Answers – Map 1 1. The large dinosaur caught the small dinosaur and ate it Evidence: Signs of a struggle in the mud with footprints overlapping and the mud disturbed 2. The small dinosaur was joined by others in the pack and they all attacked the large dinosaur Evidence: Same as above but with more small footprints coming in 3.Both dinosaurs were moving towards the same spot, maybe towards prey they both wanted Evidence: If the prey was alive, there would be signs of a struggle. If dead no sign of a struggle, maybe fossil bones
  29. 29. Suggested Answers – Map 1 4. This is a lake and they were both going to have a drink Evidence: Both sets of footprints stop as the dinosaurs reach water. There are more footprints as they walk away 5. A baby dinosaur joined its mother Evidence: Both sets of footprints join and they continue walking together 6. The large footprints cross over the smaller ones or vive versa, so they did not walk here at the same time Evidence: Larger footprints would cover the smaller ones or vice-versa and would have probably smudged them
  30. 30. Suggested Answers - Map 1 7. Both dinosaurs were walking on the mudflats but were not interested in each other Evidence: The footprints continue towards the east and show no relationship towards each other
  31. 31. Excavations continue and more footprints are revealed
  32. 32. Which of your previous ideas fits the new evidence? What happened to the 2 dinosaurs in the ground which is still hidden by the old buildings in the east? What evidence in support of your ideas would you expect to see when more footprints are uncovered? Why do you think the dinosaurs came to this mudflat in the first place?
  33. 33. Suggested Answers - Map 2 1. The larger dinosaur walked away having killed and eaten the smaller one Evidence: Only the large footprints would be seen and would be more closely spaced showing the dinosaur to be more sluggish than it was before 2. More small dinosaurs joined the struggle and killed the large dinosaur Evidence: More small footprints would be seen coming to the site and only these would be seen leaving
  34. 34. Suggested Answers - Map 2 3. Both dinosaurs walked away Evidence: Same 2 sets of footprints would be seen leaving. If they had fought, there may have been injuries and evidence for this in the footprints 4. The fight continued to the east and both dinosaurs died in the fight leaving their remains Evidence: There would be more signs of a struggle but fossil bones of the two animals would also be found (unless they were later scavenged) 5. The fight attracted lots more dinosaurs Evidence: There would be lots of different footprints all overlapping each other
  35. 35. Excavations are complete and more footprints are revealed
  36. 36. Which of your ideas best fits the new evidence? Does this evidence change your ideas about why the dinosaurs came to the mudflat? If so, why?
  37. 37. Suggested Answers - Map 3 Carnivores came to the lake to drink and search for prey Herbivores came to the lake to drink and graze Map 3 does suggest that the dinosaurs did come to the mudflat to search for prey. There is no evidence that they came to drink as well, but it is likely that they did
  38. 38. That’s All Folks!