And if the artifact is organic—like wood or bone—researchers can turn to a method called radiocarbon dating.
Understand how decay and half life work to enable radiometric dating.
Dinosaur, the common name given to a group of reptiles, often very large, that first appeared roughly 245 million years ago (near the beginning of the Middle Triassic Epoch) and thrived worldwide for nearly 180 million years.
Both men collected fossils as an avocation and are credited with the earliest published announcements in England of what later would be recognized as dinosaurs.
In both cases their finds were too fragmentary to permit a clear image of either animal.
Soon thereafter, Lewis and Clark’s expedition encountered dinosaur fossils in the western United States. The bones described had been found in 1818 by Solomon Ellsworth, Jr., while he was digging a well at his homestead in Windsor, Connecticut.
At the time, the bones were thought to be human, but much later they were identified as .
The extensive fossil record of genera and species is testimony that dinosaurs were diverse animals, with widely varying lifestyles and adaptations.
Their remains are found in sedimentary rock layers (strata) dating to the Late Triassic Epoch (approximately 237 million to 201.3 million years ago).
In 1834 a partial skeleton was found near Brighton that corresponded with Mantell’s fragments from Tilgate Forest.
It became known as the , which he named from an incomplete skeleton composed of very large bones.
Before Richard Owen introduced the term Dinosauria in 1842, there was no concept of anything even like a dinosaur.