ThE SuN HaS SeT On ThE QuArRy In WhIcH YoU WoRk You have only a headlamp to see what’s in front of you Using a small chisel you carefully chip away at rock Hours have passed and you haven’t found anything You take off your gloves and wipe sweat from your brow You are tired but you don’t take a break You have felt a sense of excitement all day You know a discovery is close You angle your chisel to the left A chunk of rock falls away and something catches your eye You softly sweep away dust and dirt with a special brush What did you find You keep chiseling slowly and carefully for days Finally the whole object is revealed It’s a skeleton The specimen is longer than your body It has large claws and a whole set of sharp teeth Do these fossils belong to a well-known animal Or have you just uncovered a previously unknown species 5
chapter WhAt ArE FOSSILS Fossils are the remains or traces of plants and animals These remains are preserved in rock Fossils can come from species that are still alive today Others are from extinct species such as dinosaurs Fossils can take several different forms Trace fossils are records of an organism’s activity They include footprints and nests Other fossils are the actual remains of a plant or animal These are called body fossils Often the remains of an organism decay over time But in some cases an impression of the organism stays in the rock This is called a mold fossil Sometimes minerals fill a mold fossil and crystalize inside it This forms a replica of the organism’s remains This replica is called a cast fossil Rock containing fossils is worn away by water and wind This erosion sometimes exposes fossils Paleontologists then uncover 1 6
and excavate the fossils Paleontologists also dig at sites where they think fossils may be buried Fossils teach paleontologists about plants and animals from millions of years ago This helps the scientists discover how plants and animals have changed over time Paleontologists also learn about extinct animals such as dinosaurs and mammoths Fossil research helps us better understand the world and its long history Hard pieces of animals are most likely to form fossils These include bones teeth and shells 7
