The carbon-14 it contained at the time of death decays over a long period of time.
By measuring the amount of carbon-14 left in dead organic material the approximate time since it died can be worked out.
The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?
But while the difficulties of single life may be intractable, the challenge of determining the age of prehistoric artifacts and fossils is greatly aided by measuring certain radioactive isotopes.
Until this century, relative dating was the only technique for identifying the age of a truly ancient object.
The results showed that Ötzi died over 5000 years ago, sometime between 33 BC. Uranium has a very long half-life and so by measuring how much uranium is left in a rock its approximate age can be worked out.
Unlike people, you can’t really guess the age of a rock from looking at it.
Here is an easy-to understand analogy for your students: relative age dating is like saying that your grandfather is older than you.
People wonder how millions of years could be squeezed into the biblical account of history. Christians, by definition, take the statements of Jesus Christ seriously.