Scientists gather information about dinosaurs by relying upon a variety of resources at their disposal, the first of which being human intuition and the ability to observe and theorize.
Sedimentary rocks (made from mud, sand, gravel or fossil shells) and volcanic lava flows are laid down in layers or beds.
They build up over time so that that the layers at the bottom of the pile are older than the ones at the top.
These rocks normally form relatively horizontal, parallel layers, with younger layers forming on top.
If a fossil is found between two layers of rock whose ages are known, the fossil's age is thought to be between those two known ages.
From the toes to the tip of the head, every bone can help us understand more about the life, culture, and people of the past.
Originally, bones were used to determine how old a person was, their race, and whether the remains were of a male or a female.Because rock sequences are not continuous, but may be broken up by faults or periods of erosion, it is difficult to match up rock beds that are not directly adjacent.The layers of sedimentary rock, or strata, can be seen as horizontal bands of differently colored or differently structured materials exposed in this cliff.The geological time scale is used by geologists and paleontologists to measure the history of the Earth and life.It is based on the fossils found in rocks of different ages and on radiometric dating of the rocks.Not every rock can be dated this way, but volcanic ash deposits are among those that can be dated.