Fossils are the remains of animals or plants that lived a long time ago. When we think of fossils, the first things that come to mind are the bones of dinosaurs; but a fossil can be anything. Footprints, flowers, even droppings; all of these things can be turned into fossils under the right conditions. A fossil only becomes a fossil when it has reached a certain age. Though there is no one age, a good rule is anything over 10, years old can be considered a fossil. The oldest fossils ever discovered are more than 3.
How to Determine the Age of a Fossil
carbon dating | Definition, Method, Uses, & Facts | Britannica
By: Tracy V. When paleontologist Mary Schweitzer found soft tissue in a Tyrannosaurus rex fossil , her discovery raised an obvious question -- how the tissue could have survived so long? The bone was 68 million years old, and conventional wisdom about fossilization is that all soft tissue, from blood to brains , decomposes. Only hard parts, like bones and teeth, can become fossils. But for some people, the discovery raised a different question. How do scientists know the bones are really 68 million years old? Today's knowledge of fossil ages comes primarily from radiometric dating , also known as radioactive dating.
Geologic Age Dating Explained
Radiocarbon dating is a key tool archaeologists use to determine the age of plants and objects made with organic material. But new research shows that commonly accepted radiocarbon dating standards can miss the mark -- calling into question historical timelines. Archaeologist Sturt Manning and colleagues have revealed variations in the radiocarbon cycle at certain periods of time, affecting frequently cited standards used in archaeological and historical research relevant to the southern Levant region, which includes Israel, southern Jordan and Egypt. These variations, or offsets, of up to 20 years in the calibration of precise radiocarbon dating could be related to climatic conditions. Pre-modern radiocarbon chronologies rely on standardized Northern and Southern Hemisphere calibration curves to obtain calendar dates from organic material.
The ability to precisely date, or identify the age of an object, can teach us when Earth formed, help reveal past climates and tell us how early humans lived. So how do scientists do it? Radiocarbon dating is the most common method by far, according to experts.