Discovery Of Dinosaurs
Discovery of Dinosaurs
We have learned most of what we know about dinosaurs from fossils, the preserved remains of dinosaursand other ancient animals and plants. Studies of the age of rocks, the changes in Earth’s magnetic fields, and the shifts in the seafloor also tell us about the age of the earth when dinosaurs lived.
Dinosaur fossils include teeth, claws and footprints. There are also dinosaur skin impressions and even feathers preserved. Scientists have even found T. Rex Poop! They call dinosaur dung a coprolite.
Fossils form when plant or animal parts or traces are covered with sand or mud and protected while minerals enter into them to harden them. Over millions of years, this sand or mud hardens into stone and fossil within it is protected, sometimes deep within the earth. If they didn’t fossilize, skeletons would turn to dust in years or mere months from wind and rain erosion.
Over million of years, even rocks move. Forces within the earth can push rock from dinosaur time closer to the earth’s surface. Erosion then exposes just a bit of a dinosaur fossil, most of which lies protected beneath the ground. Wind blows away the dust and exposes more layers of fossil rich rock. The badlands, cliff faces, and modern deserts of the North American West, China, Mongolia and Patagonia are particularly rich in dinosaur fossils. The bare desert ground, swept by wind, allows scientists and amateur prospectors the best chance to see the remains of dinosaurs.
Knowing where to look for dinosaur fossils requires knowledge of the ancient landscape. Sandstone layers produced from ancient streambeds are often the best for preserving dinosaurs. Still, luck plays a big part of fossil discoveries. Most new dinosaur discoveries are made by amateurs, not by professional researches. Sometimes children are the ones to discover the dinosaur remains.
In recent years, scientists have experimented with many methods, from radar to sound waves, to locate dinosaur bones beneath the surface of the ground. But to date, the best way to find the dinosaur is still the way it has always been done: walk the land and look down until you find a promising bit of fossil bone sticking up!
Once a dinosaur fossil is located, it is best if it is excavated by professionals.
Paleontologists are scientists who specialize in fossils. Their tools are not complicated and most of their digging methods are a century old. Researchers chip away with pickaxes, hammers and chisels to remove the rock on the top of the fossils. Sometimes they even dynamite! When close the fossil layer, scientists work with smaller tools such as awls and scrapers. The fossilized bone is removed from the ground with much of the surrounding rock still attached. At the dig, each bone or group of bones is wrapped in burlap or other fabric that is soaked in plaster. A thin separator material (such as toilet paper!) is used to keep the plaster from sticking to the bone. The plaster hardens to from a jacket that can weight several tons. The plaster cast protects discoveries, while scientists dig for more fossils.
The good weather for digging is short, but the time needed to clean fossils is long. Scientists and their assistants spend winter months in their laboratories, cleaning fossils with tiny drills. Then they begin to piece together and examine fossil fragments.
Bone studies show whether the dinosaurs suffered from injuries or disease. These studies also reveal information about how fast the dinosaur grew.
Looking at dinosaur poop under the microscope, or at the pattern of wear on a dinosaur’s teeth, can tell us what it ate.
By patiently assembling individual bones and if lucky, nearly entire skeletons, scientists can tell us more about the identity of a dinosaur.
Measurements are taken of the length and shape of the bones and compared to those of other dinosaurs that are already known. If the bones are truly different from all other known samples, then the fossil may represent a new kind of dinosaur. In a carefully detailed report approved by other scientists, a researcher then names the new dinosaur.