Dating Fossils: Techniques and Insights

The video tutorial explains various methods used by paleontologists to determine the age of dinosaur bones. It covers stratigraphy, which involves studying rock layers, and radioisotope dating, which uses the decay of uranium 235 to lead 207. The tutorial also discusses the use of volcanic rock layers and index fossils, such as trilobites, to estimate the age of fossils. These methods help paleontologists make educated guesses about the time period in which a fossilized creature lived.

What is the primary concept behind stratigraphy?

• Studying the chemical composition of fossils

• Examining the depth at which fossils are buried

• Analyzing the size of the fossil

• Measuring the temperature of the surrounding rock

Why is stratigraphy sometimes challenging?

• Fossils are often found in multiple layers

• The Earth’s layers can shift over time

• Stratigraphy requires advanced technology

• Fossils decay too quickly

What is the key requirement for using radioisotope dating?

• The fossil must be found in volcanic rock

• The fossil must contain uranium-235

• The fossil must be less than 1 million years old

• The fossil must be found near water

What does the term 'half-life' refer to in radioisotope dating?

• The time it takes for the fossil to be buried

• The time it takes for the fossil to be discovered

• The time it takes for half of the radioactive material to change

• The time it takes for half of the fossil to decay

How do paleontologists use volcanic rock layers to estimate the age of fossils?

• By measuring the temperature of the rock

• By determining the amount of argon gas in the rock

• By analyzing the chemical composition of the rock

• By examining the color of the rock

What happens to argon gas in volcanic rocks over time?

• It evaporates

• It remains constant

• It decreases

• It increases

In the example given, how old is the Triceratops fossil if the first volcanic layer is 80 million years old and the second is 70 million years old?

• 70-80 million years old

• 60-70 million years old

• 80-90 million years old

• 90-100 million years old

What are index fossils?

• Fossils that are found in the deepest layers

• Fossils that are used to date other fossils

• Fossils that are the largest in size

• Fossils that are found near water

Why are trilobites considered good index fossils?

• They are found in all layers of rock

• They are the most common fossils

• They lived during a specific time period

• They are the oldest fossils

How can the presence of a trilobite fossil help date a jellyfish fossil found nearby?

• By suggesting the jellyfish is younger than the trilobite

• By proving the jellyfish lived in a different era

• By indicating the jellyfish lived in the same era as the trilobite

• By showing the jellyfish is older than the trilobite