Dating a fossil in terms of approximately how many years old it is can be possible using radioisotope-dating of igneous rocks found near the fossil. Unstable radioactive isotopes of elements, such as Uranium-235, decay at constant, known rates over time (its half-life, which is over 700 million years).

Could Uranium 235 be used to date dinosaur bones?

To determine the ages of these specimens, scientists need an isotope with a very long half-life. Some of the isotopes used for this purpose are uranium-238, uranium-235 and potassium-40, each of which has a half-life of more than a million years. Unfortunately, these elements dont exist in dinosaur fossils themselves.

What is used to date dinosaur fossils?

Potassium-argon dating Fossils and other objects that accumulate between these eruptions lie between two different layers of volcanic ash and rock. An object can be given an approximate date by dating the volcanic layers occurring above and below the object.

Which unstable isotopes are most commonly used for dating dinosaurs?

Archaeologists routinely use radiometric dating is u-235. There are useful for dating, are also an effective.

Do fossils have uranium?

Sandstone-hosted uranium deposits commonly contain abundant organic matter, including fossil logs. The precipitation of uranium minerals is often related to reducing environments associated with these organic materials.