F23 Estimating Dinosaur Speed and Size Handout.docx (1)

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 Estimating Dinosaur Speed and Size Objectives: ● To learn how to calculate various sizes and speeds of dinosaurs based on dinosaur models and trackways. ● To better understand the link between the actual dinosaur and the ichnofossil that it creates. ● To use various techniques to estimate dinosaur linear dimensions and weight. Part I. Estimating Dinosaur Linear Dimensions Paleontologists estimate the height and length of dinosaurs by reconstructing the skeleton (conceptually and often physically) and measuring the bones. Other evidence may also be used, such as the size of footprints. In this exercise, you will use dinosaur models to discover if the model is a good representation of the actual size of the dinosaur. The British Museum of Natural History has produced a number of 1:45 scaled dinosaur models; the dinosaur models from the Museum of Natural History in Boston and the models from the Carnegie Museum of Natural History are at a 1:40 scale. However, be wary: some models may have a different scale printed on them if they do not fit the aforementioned general scales. These models are very accurate in terms of dimensions, although the soft anatomy (skin-texture, color, etc.) is less well known. 1. Select 10 dinosaur models and list each organism in the table below. Dinosaur names can be found ventrally on each model. Be sure to indicate the genus and species names of each dinosaur, if possible. 2. Determine whether the dinosaur is an Ornithischian (“bird-hipped”) or Saurischian (“lizard-hipped”). 3. Indicate the dinosaur group to which the organism belongs. If it is a saurischian, then determine if it is a sauropod or theropod. If it is an ornithischian, then determine if it is a marginocephalid (Ceratopsians and Pachycephalosaurs), thyreophoran (stegosauria and ankylosauria), or an ornithopod. 4. Use the models to indicate each dinosaur’s mode of location: quadruped or biped? 5. For footprint length, measure (in cm) each of the scale model dinosaurs. Take the measurement from the ‘heel’ of the foot to the tip of the longest toe. 6. For hip height (leg length), take the measurement from the bottom of the hind foot to the top of the sacrum (pelvic girdle or hip). Or, you can multiply the footprint length by 5. Try both methods on one or two dinosaurs to see if they differ. 7. Dinosaur length is 10x longer than the footprint length. Estimate the total length of the dinosaur by multiplying the footprint length by 10. 8. In the lab, models are grouped according to scale. Most are 1:40, but some of the smaller dinosaurs are 1:30 or 1:40. Sometimes the scale is marked on the bottom of the dinosaur, but you may need a magnifying glass to see it. 9. Convert the scaled dinosaur length to meters (100cm =1m). Record how long (in meters) each of these dinosaurs are estimated to be. 10. Research (e.g., Wikipedia) the reported size (m) of the dinosaur according to published sources (Wikipedia is not a published source – but usually cites a published source for size information.) 11. Now, calculate the percent error, using the following formula: %Error = (|Approximate - Exact| / Exact ) * 100

Dinosaur Name (Genus species) Ornithischian or Saurischian Dinosaur Group Mode of Locomotion Model Footprin t Length (cm) Model Hip Height (cm) Model Dinosaur Length (cm) Scaled Dinosaur Length (m) Real-Life Length (m) Percent Error (%) Example: Chicken Saurischian Theropod Bipedal 0.5 2.5 5 0.5 0.7 28.6 Tyrannosaurus Saurischian Theropod Bipedal 2 7 21 8.4 12.4 32.3 Malasaura Peeblesorum Ornithischian Hadrosaurid Facultative Bipedal 1.1 6.8 20.7 8.3 9 7.8 Acrocanthosaurus Atokensis Saurischian Theropod Bipedal 2.1 6.5 25.1 10 11.5 13 Euoplocephalus Tutus Ornithischian Ankylosaurid Quadrupeda l 1.4 3.5 16 6.4 6 6.7 Apatosaurus Saurischian Saurischia Quadrupeda l 2.1 8.5 40.5 16.2 22.8 28.9 Dilophosaurus Wetheril Saurischian Theropod Bipedal 1.6 6.2 20.4 8.2 7 17.1 Stegosaurus Armatus Ornithischian Ankylosaurid Quadrupeda l 1 5 16.5 6.6 9.1 27.8 Gallimus Bullatus Ornithischian Theropods Bipdeal 1 5.5 13.4 5.4 6 10 Therizinosaurus Ornithischian Theropods Bipedal 2 6 16.5 6.6 10 34 Triceratops Ornithischian Ceratopsidae Quadrupeda l 1.5 6.2 19 7.6 9 15.6

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 Part II. Testing the Method of R. McNeill Alexander (1989) At first thought, it might seem nearly impossible to estimate the speed of a dinosaur since no one has ever seen a dinosaur alive and all we have are bones. However, we don’t just have dinosaur bones! We also have dinosaur footprints! So, even though we can’t observe a live dinosaur, we can estimate a dinosaur’s speed based on indirect evidence, thanks to a method developed by British researcher R.M. Alexander. In the following exercise, you will estimate the speed of the dinosaurs that make footprints. 1. In part I, you calculated the hip heights for each dinosaur. Copy these hip heights recorded in Table 1 and paste them into the column labeled “hip height” in Table 2. 2. You are provided the measured stride length (m) for each dinosaur. Remember that trackways consisting of two footprints from the same foot provide us with the information necessary to measure stride length, with the measured stride length being the measured distance between footprints from the same foot. These are recorded in the column labeled “stride length.” 3. Calculate the relative stride length by dividing the measured stride length by the hip height: Relative Stride Length = Stride Length (m) / Hip Height (m) Record this in the column labeled “relative stride length.” Remember relative stride length is dimensionless. 4. Once we calculate relative stride length, then we can estimate the relative speed of each dinosaur. Use the information below to estimate the relative speed of each dinosaur and record this in the column labeled “relative speed.” a. If the relative stride length is <2, then the dinosaur is walking b. If the relative stride length is between 2 - 2.9, then the dinosaur is trotting c. If the relative stride length is >2.9, then the dinosaur is running.

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 5. Dimensionless speed can be found via relative stride length using the graph below. To estimate dimensionless speed, find the intersection on the line in the graph that corresponds to relative stride length on the Y-axis; move downward and find the corresponding dimensionless speed on the X-axis. To check if you estimated dimensionless speed, you can plug the relative stride length into the linear regression equation to calculate the actual dimensionless speed: Dimensionless Speed = [Relative Stride Length x 0.83] - 0.7 Calculate and record dimensionless speed into the column labeled “dimensionless speed.” 6. Actual speed can be calculated by multiplying the dimensionless speed and the square root of the product of leg length and the acceleration due to gravity: Speed (m/s) = dimensionless speed x [hip height (m) x 9.81 (m/s 2 )] Record this in the column labeled “Estimated Speed (m/s).” 7. Now, multiply the speed in m/s by 2.25 to convert to miles per hour (mph).

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 Part III. Answer the following questions pertaining to Part I and Part II. 1. As speed increases from walking to running, what happens to stride length? For the dinosaurs whom’s relative speed was running their stride length increased massively for example the Velocirpator whose original stride is at 0.63m who went to 4.2m as a result. 2. Alexander (1988) states that animals are walking at dimensionless speeds below .7 but switch to a running gait at higher dimensionless speeds. Do your results agree or disagree with this? Explain. I agree with the statement due to the change in pace between the dinosaurs who were walking, trotting, and running. 3. If a dinosaur the size of Allosaurus were trailing the Triceratops, would the Triceratops be able to escape? Why? No because the Allosaurus is slightly faster than the Triceratops. Allosaurus has a greater stride length as well as relative. 4. You can compare speed and relative stride length to ascertain how organisms could interact (i.e., faster than, slower than, etc.) Use the data that you collected in Part II to create a scatter plot comparing relative stride length to estimated speed (m/s) for ornithischian and saurischian dinosaurs. Be sure to label your axes, create a legend and include a trendline with the equation for each dataset. a. Copy and paste your graph in the space below: https://onedrive.live.com/edit.aspx?resid=FE767F1EACB5201F!11718&ithint=file%2cxlsx&wdo=2&aut hkey=!AKSn5LphYjivHHo b. Which group of dinosaurs is faster: Saurischians or Ornithischians? Explain.

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 The saurischians were overall faster according to our graph. 5. Chickens are extant descendants of theropod dinosaurs. How do the speeds of chickens compare to other theropods? How do their speeds compare to dinosaurs of similar size (e.g., Hypsilophodon (ornithischian) or Compsognathus (saurischian)? Hypothesize why this trend could occur. Compared to Hypsilophodon and Composognathus, the chicken stomps them in overall speed and estimated speed at 7.61 and 3.38 compared to Hydro and Comp which they respectively measure at: 1.03 and 0.46. However, the dinos were walking compared to the chicken which was running. So, it is safe to assume that the dinos would be faster if they decided to run. 6. Now, apply this method to yourself. Follow the steps for Part I and Part II to estimate your walking and running speeds. a. How do the speeds of these extinct organisms compare to your walking and running speed? I would be faster than the majority of them due to being smaller and agile. b. Which dinosaurs could you outrun? Majority of them except for Velociraptor. 7. What are two potential sources of error in this method of estimating speed? Assume that the measurements are made accurately and focus on the assumptions of the method itself.

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 north c. Observe the footprints. How many types of footprints do you observe? What types of dinosaurs could have made these tracks? sauropod, stego, and theropod. t-rex and stegosaurus would be possible organisms. d. Approximately, how many different organisms made these trackways? 5 e. Propose and describe a likely scenario that could have occurred between the dinosaurs in these trackways. Be sure to explain your reasoning. predators hunting for prey possibly. 5. Now, choose three trackways (one theropod and two sauropods) from the Ozark site. Measure the footprint size in mm of each sauropod and theropod footprint. (for sauropods use hind prints only). Calculate the mean footprint size for each dinosaur. Record this information in the table below. If using the footprint handout, note that the map scale is 1:40. Therefore, you need to multiply the mean value of footprint size by 40 to get the actual size. Divide by 1000 to convert to meters. 6. Calculate leg length based on the estimated footprint size. Research has shown that dinosaur hind legs are usually about five times longer than hind feet; thus, leg length can be estimated by footprint size. 7. Measure the stride length of each set of dinosaur tracks. It is important to remember that stride is not from one footprint to the next; stride length is the distance from the toe (or heel) of one footprint to the toe (or heel) of the next print made by the same foot (e.g. toe of left footprint to toe of next left footprint, etc.) Calculate the mean stride length for each dinosaur. Remember to make the scale adjustment and convert to meters. 8. Calculate relative stride length (no units): Relative Stride Length = stride length (m) / leg length (m) 9. Dimensionless speed can be found via relative stride length using the equation: Dimensionless speed = (Relative Stride Length x 0.83) – 0.7 10. Finally, actual speed can be calculated by multiplying dimensionless speed and the square root of the project of leg length and thee acceleration due to gravity Speed (m/s) = dimensionless speed * [leg length (m) * 9.81 m/s 2 )] 0.5 11. Multiply the speed in m/s by 2.25 to convert to miles per hour.

GEOL 207: Dinosaur World Name: Lab Section: 200 500 501 502 503 504 505 Measurements Theropod (Trackway 1) Sauropod (Trackway 2) Sauropod (Trackway 3) Footprint (m) 0.8 0.4 0.52 Leg Length (m) 4 1.6 2.08 Stride Length (m) 2.2 2.68 2.92 Relative Stride Length 0.55 1.68 1.4 Dimensionless Speed 0.24 0.69 0.46 Speed (m/s) 1.5 2.75 2.09 Speed (miles/hr) 3.38 6.19 4.7