most fossils are dug from
Paleontologistâs estimate that only a small percentage of the dinosaurs that ever lived have been or will be found as fossils, because their bodies simply decayed. The word fossil comes from the Latin word fossils, which means, âdug upâ. Most fossils are excavated from sedimentary rock layers. Sedimentary rock is rock that has formed from materials like sand, mud, and small pieces of rock. Over long periods of time, these small pieces of debris are squeezed and are buried under more and more layers of sediment that piles up on top of it.