Radiocarbon dating is used to measure the age of fossils Chat sex free
Now, however, those doubts have been put to rest thanks to the discovery of what may be the world's oldest dinosaur bones.
The remains of the Nyasasaurus parringtoni, a labroador-sized creature with a 5-foot tail, are 10 to 15 million years older than any other dinosaur fossils found thus far.
So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil.
In the same way, geologists figure out the relative ages of fossils and sedimentary rock layers; rock layers, and the fossils they contain, toward the bottom of a stack of sediments are older than those found higher in the stack. We only know about extinct groups like dinosaurs, ammonites and trilobites through fossils.
Absolute dating is the process of determining an age on a specified chronology in archaeology and geology.
Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.
These break down over time in a process scientists call radioactive decay.
Archaeologists have long used carbon-14 dating (also known as radiocarbon dating) to estimate the age of certain objects.
Radiometric dating relies on the properties of isotopes.
These are chemical elements, like carbon or uranium, that are identical except for one key feature -- the number of neutrons in their nucleus.
Scientists use two kinds of dating techniques to work out the age of rocks and fossils. This considers the positions of the different rocks in sequence (in relation to each other) and the different types of fossil that are found in them.