NOTE: This is an earthcache; there is no physical container to find at the coordinates. To get your smiley for the cache, e-mail your answers for the questions below to the cache owner.
1- Describe and name 2 types of fossilized corals in the rock stones you see here.
2- Classify the ratio of coral fossils to the solid rock matrix. The coral fossils are: 1) Abundant = 30-50% 2) Common = 10-30% 3) Sparse = 2-10% or 4) Trace = less than 2%
3- Do you think these coral rock stones are a good choice for this area? Give your reasoning.
Universal Studios CityWalk Orlando is open year-round. You will not need a theme park ticket to complete this earthcache as the coordinates are outside the parks. It is free to visit Universal Studios CityWalk and free to park most days in the parking garage after 6:00pm. If you would like to go inside the theme parks there is a fee.
Are you ready to discover some Jurassic rocks?
Stony Corals
Modern reef building corals, also known as stony corals, are thought to have come from the Jurassic period 160 million years ago. During this time, there was a major increase in the diversity of corals of more than 200 categories. Jurassic corals played a crucial role in shaping marine ecosystems. These corals are still seen today and are commonly found in tropical oceans.
Stony corals or Scleractinian (SCLER-ac-TIN-ee-an) corals are colonial organisms with individual polyps. These coral polyps build their exoskeletons by secreting calcium carbonate from their base. These external skeleton cups, called corallites, are hard in nature and are the primary material for reef structure building. Stony corals grow best in shallow sunlit water, in less than 36 feet.
Common Types of Stony Corals
Pillar and Branching Coral
Pillar corals grow in clumps and often resemble fingers or cigars. They grow directly from the sea floor and don’t have any branching. Pillar corals grow on both flat and sloping surfaces and are one of the few types of corals where the polyps can be seen feeding during the day.
Branching corals have numerous branches and usually even secondary branches. Some common types of branching corals found in the Caribbean and Florida include Staghorn, Elkhorn, and Clubbed Finger Coral. Due to their branching shape, these corals are somewhat fragile when they are alive and, when seen as fossils, they are often broken fragments in the coral rock.
Brain and Honeycomb Coral
Brain corals have sphere shapes and grooved skeletal patterns that look like wrinkles in a human brain. They have a hard surface which protects them from storms and fish. To eat, they extend their tentacles at night and retract them in the day for protection. Brain corals are usually easy to identify as fossils because of their irregular maze-like patterns.
Honeycomb corals have closely packed polygon-shaped corallites that look like a honeycomb structure. These corals are colonial and can form in massive dome shapes. They have tiny holes in the walls between corallites which is possibly how they transfer nutrients between polyps and throughout the colony. Fossilized honeycomb coral can be identified by looking for prismatic tight tubes with holes.
Lettuce Coral
Lettuce corals have broad and wavy plate extensions that look like a head of lettuce. Horizontal forms usually have corallites on both sides, but vertical forms will usually only have corallites on one side. They grow from a single base and can range from 4 inches to 3 feet. Lettuce corals are sturdy and can live in shallow or deep water, dark crevices, and turbulent waters. To identify a fossilized lettuce coral, look for the wavy leaf-like structure with a pattern of ridges kind of like a ridged potato chip.
Star Coral
Star corals have round close together corallites with star shapes inside. They usually grow in a boulder or dome shape and have a somewhat smooth looking appearance with dimples. Star corals are often found growing on rocks in shallow areas and are common in the Caribbean and Florida. While looking to identify a fossilized star coral, look for a sunburst or star pattern with circles around it spaced closely together.
Reef to Rock
Corals can form into a type of limestone or coral stone through a process called lithification. When a coral dies, its skeletons of coral polyps are buried under layers of sediment. Over time, the calcium carbonate of the skeleton is gradually replaced by other minerals. As the surrounding sediment is cemented together, it forms a solid rock matrix around the coral. This rock matrix preserves the coral’s structure and is the reason why you can see corals in the rocks here!
Questions:
Now it is time for the questions. To get credit for the cache, please answer the questions below. When answering the questions, do your best. It is more important that you learn a new concept about our earth and can apply your knowledge rather than have a precise answer.
If you struggle identifying a fossilized coral exactly at the coordinates feel free to walk along the coral rocks until you see something you can identify.
1- Describe and name 2 types of fossilized corals in the rock stones you see here.
2- Classify the ratio of coral fossils to the solid rock matrix. The coral fossils are: 1) Abundant = 30-50% 2) Common = 10-30% 3) Sparse = 2-10% or 4) Trace = less than 2%
3- Do you think these coral rock stones are a good choice for this area? Give your reasoning.
Thank you for visiting this earthcache. Please send your answers to the above questions to the cache owner. In your "found it" log, feel free to write about your experience, but don't include the earthcache answers. We hope you enjoy discovering some Jurassic Rocks!
Sources:
https://learningzone.oumnh.ox.ac.uk/corals
https://www.coralsoftheworld.org/page/evolution/
https://www.uky.edu/KGS/fossils/fossil-coral.php
https://www.sdnhm.org/exhibitions/fossil-mysteries/fossil-field-guide-a-z/brain-coral/
https://www.britannica.com/science/Jurassic-Period/Paleoclimate
https://en.wikipedia.org/wiki/Scleractinia
https://edis.ifas.ufl.edu/publication/FA210
https://www.britannica.com/science/coral-reef
https://en.wikipedia.org/wiki/Pillar_coral
https://en.wikipedia.org/wiki/Brain_coral
https://en.wikipedia.org/wiki/Diploastrea_heliopora