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Name: Ali Butt
TA: Carley Wilshire
Lab 8: Fossils
GEOL 1122
This lab covers fossils, both the processes that make them, what the tell us, and making observations and identifications about them. Please watch the videos on iCollege and use the hand out to complete this lab. You are also welcome to use your textbook. Part One: Fossil Specimens
1)
A deer died 500 years ago. Are the remains considered a fossil? Why or why not? (3 pts)
Since a specimen of a fossil would need to be at least 10,000 years old, the deer would not qualify as a fossil. This is due to the lengthy nature of the fossilization process.
2)
Describe the preservation potential for each specimen. Explain your reasoning. (3 pts each)
a.
Sea turtle:
Because of their strong shells, sea turtles have a high potential for preservation. Because they are composed of bone, these shells have a good chance of fossilizing.
b.
Dolphin:
Dolphins have a strong chance of being preserved as well. They have a strong skeleton that is good for fossilization. They inhabit marine habitats, just like sea turtles, where fossilization conditions are frequently favorable.
c.
Jellyfish:
The potential for jellyfish preservation is low. They don't have any hard pieces, which are the portions of an organism most likely to fossilize—like bones or shells. Their fragile, gelatinous bodies swiftly disintegrate after death, leaving little to no material for fossilization.
d.
Centipede:
The possibility for preservation of centipedes is medium. Although they do possess hard exoskeletons, their terrestrial habitats do not provide the same conditions for fossilization that marine ecosystems offer.
3)
Fossils are common in all three types of rocks. True or false? Explain your reasoning. (3 pts)
The three primary types of rock are sedimentary, metamorphic, and igneous. Fossils are typically found in sedimentary rocks. So, the statement is false.
4)
How does the rate of burial affect the potential for fossilization? (2 pts)
The possibility for fossil preservation is closely correlated with the rate of burial, i.e. The greater the rate of burial, the greater the likelihood of preservation. The fossilization process depends on the remains being quickly buried beneath a layer of silt, which shields the remains from physical and biological processes that would otherwise destroy them.
5)
You find a site filled with fossilized insects, leaves, and hard parts from fish, but you find
no worm fossils. Your partner concludes that no worms lived at the site at that time. Explain why the conclusion might be flawed and list other forms of evidence that might indicate that worms did in fact live among these other organisms. (2 pts)
The results could be malfunctioned or faulty, since it would be difficult to determine whether worms were actually there because they do not have a high preservation potential. However, traces or imprints of a worm's movement can be used to determine whether or not it lived there.
6)
Environments play a crucial role in an organisms chance of fossilization. Think about the environment each of the below lived in. Then, explain which organisms had a higher or lower chance of fossilization based on the particular habitat. (3 pts each)
a.
A salamander in a creek vs. woody plants in a swamp
b.
A shark in the Pacific Ocean vs. a deer on top of a cliff
When an organism is promptly buried after dying, it stops decaying and allows its remnants to be preserved. This process is known as fossilization. a) A salamander. If a salamander were in a creek, the water's current might bring silt that would swiftly cover its body and raise the likelihood that it would fossilize. However, woody plants in a swamp might not bury themselves as quickly, which would lessen the chance that they would become fossilized.
b) A shark. Because of the sedimentary conditions and low oxygen levels at the ocean floor, a shark in the Pacific Ocean is more likely to fossilize and remain preserved. A deer perched atop a cliff, on the other hand, has less of a chance because terrestrial habitats typically don't provide the right circumstances for fossilization.
7)
What is the difference between a fossil and artifact? (2 pts)
The primary distinction between fossils and artifacts is that the former are the preserved remains of living things, while the latter are the remains of objects made by humans. Unlike artifacts, which are significant in terms of history and anthropology, fossils are also valuable from a scientific standpoint. Fossils include things like seashells, animal bones, leaf impressions, footprints that have been preserved in rock. Artifacts include things like vases, pyramids, arrowheads, etc.
8)
Use the following 3D model to answer the questions: https://sketchfab.com/3d-models/heliophyllum-halli-pri-70755-
9ddbca9ef7384ea7b748a7f219cc9156
a.
Is this a body or trace fossil? (1 pt)
Body fossil.
b.
Are solitary or colonial corals represented? (1 pt)
Solitary corals.
c.
To which phylum does it belong? (1 pt)
It belongs to phylum Cnidaria, which also includes modern-day corals, jellyfish, and sea anemones.
9)
Use the following 3D model to answer the questions: https://sketchfab.com/3d-models/petrified-wood-2-94d1b3f178af47cd92aca365c634da41
a.
Is this a fossil or artifact? Why? What is it? (3 pts)
It's a fossil, this. It is wood that has been petrified as a result of the fossilization process, which takes millions of years and replaces the organic substance in wood
with minerals, usually silica. The original wood's structure and details are preserved through this technique.
b.
What is the primary mode of preservation? How do you know? (2 pts)
Permineralization is the main preservation method. The intricate texture and structure of the wood, which demonstrate the replacement of the original organic substance by minerals, make this clear.
10) Open the 3D models of these two fossils and compare this for this question:
https://sketchfab.com/3d-models/brachiopod-platystrophia-cypha-pri-76923-
1e28ac9ff111488ea54f581cc286b87e
https://sketchfab.com/3d-models/bivalve-mercenaria-mercenaria-pri-76728-
6f5f534f002b4402b2043fa09ed6441a
a.
Are these body or trace fossils? (1 pt)
Body fossil.
b.
Explain the major differences you see between these fossils. (2 pts)
Primarily the fossil's form. One features grooves, while the other is more rounded.
c.
To which two phyla do these specimens belong? (2 pts)
The Brachiopoda contains the first, whereas Mollusca contains the others.
11) Use this 3D model to answer these questions: https://sketchfab.com/3d-models/pal617525-giant-ground-sloth-dung-vcu-3d-4092-
fa1a828c79e54f41829b63ff32915530
a.
Is this a trace or body fossil? What does it represent? (2 pts)
Trace fossil. It represents the feces or stools from the animal.
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b.
What sort of information could be obtained from this particular fossil? (2 pts)
Researchers can learn more about the kinds of plants and other materials that the fossil eats by examining the makeup of its excrement. They may also be able to identify any parasites or other organisms that may be living in its digestive system. The habitat and ecology in which the sloth lived may also be inferred indirectly from this fossil.
12) Use this 3D model to answer these questions: https://sketchfab.com/3d-models/cephalopod-baculites-sp-pri-70605-
c1a09417fbe546819938e36f5c541c7b
a.
Describe what you see in this model. (2 pts)
The model depicts a long, conical-shaped, straight, and slender fossil. Its length is
covered in a succession of transverse lines or ridges.
b.
Is this a nautiloid or ammonoid? (1 pt)
An ammonoid.
c.
What is a key characteristic that can be used for identifying this type of cephalopod? (1 pt)
Unlike the majority of ammonoids, which have coiled shells, this species of cephalopod has an elongated, straight shell with transverse ridges.
d.
Is this type of cephalopod extant (currently living) or extinct? (1 pt)
Extinct. There are no more of this kind.
13) Use this 3D model to answer the questions: https://sketchfab.com/3d-models/vertebrate-
fish-pri-53568-e62fbf61257c462c842ac31354de49a9
a.
What type of preservation is this? How can you tell? (2 pts)
It might be mold. From the appearance, it appears that the rock contains a mold that, when plaster is poured into, will recreate the fish on the rock.
14) Use this 3D model to answer the questions: https://sketchfab.com/3d-models/bivalve-
ostrea-coxi-pri-40844-e6938b1c171d48ef8113bfcd9e7e3d9b
a.
Why do you think the bivalve has a hole in its shell? (1 pt)
According to the image caption, a predatory snail produced it.
b.
What type of mollusk might have made the hole? (1 pt)
The bivalve shells in the photograph have a hole on them that is not a natural hole. This has to have been created by a cannibal or predatory snail that ate the snail to create the hole in its shell.
15) Use this 3D model to answer the questions: https://sketchfab.com/3d-models/theropod-
footprint-3e4541927c444a2e820c9cde01858ace
a.
Is this a body or trace fossil? (1 pt)
It is a trace fossil.
b.
Does this specimen reflect the presence of a vertebrate, invertebrate, microfossil, plant or artifact? (1 pts)
The size and shape of the footprints on this specimen suggest the presence of a vertebrate.
16) Use this 3D model to answer the questions: https://sketchfab.com/3d-models/trilobite-
flexicalymene-meeki-pri-41460-f9196ab8802245988a3542f1eb1c0f3c
a.
What phylum does this specimen belong to? (1 pt)
The specimen is a member of the phylum Arthropoda, a broad class of invertebrates distinguished by the presence of an exoskeleton and jointed appendages. Insects, spiders, crustaceans, and trilobite, like the one in the 3D model are examples of arthropods.
b.
Is it extant (currently living) or extinct? (1 pt)
Millions of years ago, trilobites became extinct.
c.
What are two examples of other organisms found in this phylum? (2 pts)
Spiders and Crabs.
17) Use this 3D model to answer the questions: https://sketchfab.com/3d-models/dinosaur-
vertebra-0e6f2b64c0a94608bae793ab22be1d05
a.
What is this specimen?
A vertebra, or section of a dinosaur's backbone, makes up the specimen.
b.
What is the mode of preservation common for such specimens? How can you tell (consider if you had a specimen you could handle)? (2 pts)
Permineralization is a frequent preservation method used for these specimens. The process of fossilization known as permineralization occurs when mineral deposits create internal casts within living things. When mineral-rich dissolved water seeps into porous tissue, like bone, the minerals precipitate out of solution, depositing a crystalline cast inside the cells of the organism and solidifying the tissue.
18) Using this 3D model (
https://sketchfab.com/3d-models/mosquito-in-amber-
53a61d58c09b4d2ab30e269aa3e22078
) explain how this organism became a fossil. (2 pts)
When a mosquito became stuck in the sticky resin that some trees make, it solidified over
time and preserved the insect's body in amazing detail because the glue was waterproof and airtight. This is how a mosquito becomes a fossil in amber.
Part Two: Dinosaur Tracks
How do scientists know how fast dinosaurs run? In this part of the assignment, you are going to be introduced to how we can determine this from dinosaur trackways.
Trackways provide a wealth of information as to the size of an animal and how it moved. Interpretation is influenced by several factors including whether an animal was bipedal (walking on TWO feet such as T-rex or human) or whether instead the animal was quadrupedal (walking on FOUR feet such as a Triceratops, giraffe, or dog). Additional factors for consideration include
the weight of the animal, how the foot is placed, how the animal stood, number of digits, surface of movement, and quality of preservation.
Part A: Finding Correlations
The first part of this activity examines the relationship between foot length, leg length, stride length, and speed. You are welcome to use your own measurements if you have access to a tape measure and stop watch, or you can answer the questions using the data provided. If you use your own measurements, make sure you report YOUR VALUES everywhere we are providing a value.
What is the relationship between foot length, leg length, stride length, and speed?
1)
Remove your shoes and measure the length of one foot
in cm:
Provided: 24 cm
2)
Measure the distance from your hips to the floor
(leg length) in cm:
Provided: 98 cm
3)
Divide your hip height by your foot length to get the ratio for these measurements (1 pt):
Answer: 98 cm / 24 cm = 4.08 cm
(note if you calculated this from provided or optional measurements)
The ratio between footprint length (FL)
and hip height (h) – also called leg length – is different for different groups of dinosaurs, but generally, the hip height (or leg length) of a bipedal dinosaur is approximately 4x larger than footprint length (Alexander, 1989).
Speed can then be calculated as relative speed,
which is stride length (SL)
divided by hip height (h)
.
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Next, you will examine how stride length changes as you go from walking to running. 4)
What do you think happens to your stride length the faster you run? Does it increase, decrease, or stay the same? (1 pt)
Your stride length usually lengthens as you run faster. This is because you have to take longer steps in order to cover more ground in less time, which causes your stride length to rise.
If you want to do the next part, you need to measure a straight, unimpeded distance of 20 m (maybe outside on the sidewalk or driveway) and have a stopwatch ready. Or, you can use the numbers we have provided.
5)
Walk the distance and count how many times your LEFT food hits the ground.
Provided: 12
6)
Record how many seconds were needed to complete the 20 m at a walking pace.
Provided: 15.5 seconds
7)
Determine your actual speed by dividing 20 m by the number of seconds. (1 pt)
Answer: Speed = Distance / Time = 20m/15.5s = 1.29 m/s
(note if calculated from provided or optional numbers)
8)
Run the distance and count how many times your RIGHT food hits the ground
Provided: 8
9)
Record how many seconds were needed to run the 20 m
Provided: 7.75 seconds
10) Determine your actual speed by dividing 20 m by the number of seconds (1 pt)
Answer: Distance = 20 m, Time = 7.75 s; Speed = Distance / Time; Speed = 20 m / 7.75 s = 2.58 m/s
(note if calculated from provided or optional numbers)
You should notice that your stride length increased while running compared to walking!
11) Determine your stride length and then your relative speed:
a.
Walking: Divide 2000 cm by the number of strides you listed for #5
Answer: Stride length = Distance / Strides = 2000 cm / 12 = 166.67 cm/stride
(note if calculated from provided or optional numbers)
Your relative speed is your stride length divided by your hip height (#2)
Answer: Relative speed = 166.67 cm / 98 cm = 1.70
(note if calculated from provided or optional numbers)
b.
Running: Divide 2000 cm by the number of strides you listed for #8
Answer: Stride length = Distance / Strides = 2000 cm / 8 = 250 cm/stride
(note if calculated from provided or optional numbers)
Your relative speed is your stride length divided by your hip height (#2)
Answer: Relative speed = 250 cm / 98 cm = 2.55
(note if calculated from provided or optional numbers)
Key Points
There is a direct relationship between leg length and the length of the stride of a walking individual
There is a direct relationship between leg length and the length of the stride of a running individual
Stride length divided by hip height is relative speed. Hip height is 4x foot length for bipedal dinosaurs
Paleontologists apply this information to trackways in order to calculate the height and speed of dinosaurs. The ratio of stride length divided by leg length can be used to tell if a dinosaur was walking, trotting, or running. The following numbers are used to interpret the speed:
Dinosaur stride length
hip height (aka leg length)
Speed
< 2.0
Walking
2.0 – 2.9
Trotting
> 2.9
Running
Part B. Applying Your Knowledge
Now let’s take measurements from dinosaur trackways. If you are ever on campus, these are in the hallway outside Sparks Hall room 131!
T-rex
The length of a single footprint is 56 cm
12) Determine the hip height by multiplying the length of the footprint by 4. (1 pt)
Answer: Hip height = Length of footprint × 4
Hip height = 56 cm × 4 = 224 cm
The stride length is 470 cm
13) Calculate the relative speed by dividing the stride length by the hip height. (1 pt)
Answer: Relative speed = 470 cm / 224 cm = 2.098
14) Using the table above, what speed is the T-rex moving? (1 pt)
Answer: T-rex is trotting.
Velociraptor
The length of a single footprint is 19 cm
15) Determine the hip height by multiplying the length of the footprint by 4. (1 pt)
Answer: Hip height = 19 cm × 4 = 76 cm
The stride length is 250 cm
16) Calculate the relative speed by dividing the stride length by the hip height. (1 pt)
Answer: Relative speed = 250 cm / 76 cm = 3.289
17) Using the table above, what speed is the velociraptor moving? (1 pt)
Answer: Velociraptor is running.
Look at the table below of maximum speeds for several groups of dinosaurs and humans. Tracks from T-rex come from large theropods. Tracks from velociraptors come from small theropods. Could humans outrun the animals that left these tracks? Why or why not? (2 pts each)
18) T-rex:
Maximum speed: 20 km/h.
A T-rex cannot outrun a human. The T-rex was a giant theropod with a maximum speed of 20 km/h, although despite its slower pace, its massive size would probably allow it to cover ground swiftly. T-rex could also pursue prey over short distances because of their lengthy strides.
19) Velociraptor:
Maximum speed: 40 km/h Humans are also unable to outrun a velociraptor. Small theropods with a reputation for speed and agility were called velociraptors. They might have moved as fast as 40 km/h, therefore they were probably quick hunters who could catch up to their prey in brief bursts of speed.
20) Could the person who we measured at the beginning (or YOU if you were able to take these measurements yourself) outrun either animal? Hint: to convert meters per second (from #10) to kilometers per hour, multiple by 3.6). Why or why not? (2 pts)
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Given that the human maximum speed recorded at 23 km/h may be converted to about 82.8 km/h, it is improbable that the individual recorded at the outset could outpace a Velociraptor or a Tyrannosaurus Rex. Because of their adaptations for predation, both of these dinosaurs had higher maximum speeds (20 km/h for T. rex and up to 40 km/hr for Velociraptor). They were also probably considerably more effective runners over short distances. That a person could outrun these dinosaurs is therefore unlikely.
Animal
Maximum speed
Sauropodomorphs
5 km/hr
Stegasaurs and ankylosaurs
6-8 km/hr
Sauropods (
Apatasaurus
)
12-17 km/hr; maximum 20-30 km/hr
Large theropods (
Tyrannosaurus
) and ornithopods
20 km/hr
Ceratopsians (
Triceratops
)
Up to 25 km/hr
Small theropods and ornithopods
Up to 40 km/hr
Ornithomimids
Up to 60 km/hr
People
23 km/hr
Usain Bolt
45 km/hr