Download Horse Fossil Capital of the World Questions

Horse Fossil Capital of the World
Questions
Name _______________________________________________
1. Explain how sinkholes are created.
2. Why are sinkholes common in Florida?
3. How would a sinkhole become a pond?
4. What climate change occurred 38 million years ago? How was the North American landscape altered?
5. How did the early species of horses adapt their diet to the to the dramatic climate change of
38 million years ago?
6. Explain two important tooth adaptations of evolving horse species that made them efficient
grazing animals.
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7. How did the development of a horse’s foot from three padded toes to a single foot covered in hard horn
contribute to horse survival?
8. Define “vestigial”. What part of extinct horse’s foot became vestigial?
9. Explain how a fossil is created by the mineralization process. Option: draw a diagram to explain the process.
10. Draw an articulated limb of a fossilized horse and then some bones that are “in situ”.
11. Were the massive gomphtheres vegetarian or carnivorous? They are related to what animal of today?
12.
Essay: Explain the results of the massive extinction event that occurred at the end of the last Ice Age
about 10,000 years ago. What animals became extinct within the region now known as Florida? Do you believe humans had a part in the extinction of the horse in America at the end of the Ice Age? Explain your answer in detail.
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Horse Fossil Capital Questions
Answer Key
1. Explain how sinkholes are created.
The subterranean geology of Florida is known as “karst” which is lime rock strata made porous, like
swiss cheese, by thousands of years of water moving from high to low elevations. Caves are sometimes created as acidic rainwater continues to dissolve the lime rock that lie underground. The sheer
force of underground moving water breaks away weakened or “rotten rock”. The ground above an
underground cave may suddenly cave in as it is no longer supported. The caved in feature appears as
a large hole in the earth’s surface. That feature is called a “sinkhole”.
2. Why are sinkholes common in Florida?
Because the entire Florida peninsula is composed of lime stone, the result of being the bottom of an
ancient ocean for millions of years, sinkholes are a common place subterranean feature. Sinkhole
formation is an ongoing process. Sometimes they are small but every once in a while a sinkhole of
several acres in surface area occurs swallowing up whatever is on the ground surface.
3. How would a sinkhole become a pond?
Sometimes these holes fill with rain and surface water to become ponds or lakes.
4. What climate change occurred 38 million years ago? How was the North American landscape altered?
38 million years ago there was a dramatic shift from a tropical climate to a dry and cool climate.
Tropical forests and swamps were transformed over the years into woods and vast grasslands.
5. How did the early species of horses adapt their diet to the to the dramatic climate change of 38 million
years ago?
Horses evolved from being browsers that ate mostly shrubs, tree leaves and grass into grazing animals that eat mostly grass.
6. Explain two important tooth adaptations of evolving horse species that made them efficient grazing animals.
Horses adapted over time to being full time grazers by developing molars that had concentric ridges
that made for good grinding of tough grasses. Their molar or grinding teeth also developed into features that grew constantly as they were worn down. This ability of teeth to grow throughout the animal’s lifetime is called “hypsodontic” and is also common to rodents.
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7. How did the development of a horse’s foot from three padded toes to a single foot covered in hard horn
contribute to horse survival? About 20 million years ago as the climate of North America was changing from tropical to dry and colder, ground surfaces went from being soft and wet (boggy) to hard
and dry. The Ice Age also brought icy and snow covered grasslands during the long winters. Horses
could get far better traction when running at a hard gallop on hard surfaces with a single hard hoof
attached to each leg.
8. Define “vestigial”. What part of extinct horse’s foot became vestigial?
“Vestigal” means a part of an animal’s anatomy that still is apparent but is non-functional. A good
example would be the human appendix. The two side toes on extinct horse’s feet became vestigial.
Small bones alongside the horses’s cannon bone (or metacarpal) called splint or side bones remain
and can be seen in X-Rays. On the inside of modern horse’s leg are located leather like round patches called “chestnuts”. These are all that remain of the hoof pads of ancient, extinct horses.
9. Explain how a fossil is created by the mineralization process. Option: draw a diagram to explain the process.
In the mineralization process, minerals such as calcium carbonate in the rock strata are dissolved in
water. The mineral laden water then infiltrates the cells of an animal’s bones. The water evaporates
and leaves the minerals behind in the bone cells. The minerals harden into rock form.
10. Draw an articulated limb of a fossilized horse and then some bones that are “in situ”.
Using the internet to find a diagram of an extinct horse’s skeleton may be of help. Remember that
the article explains that “articulated” means that the bones are found in place as they are located to
form a limb. “In situ” means in place but not always found in an orderly fashion, but scattered
about.
11. Were the massive gomphtheres vegetarian or carnivorous? They are related to what animal of today?
Gomphotheres were vegetarians and used their huge tusks to tear up tree and shrub limbs and roots to eat.
They are distant relatives of elephants.
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