Plants that were alive at the time of the dinosaurs have left their fossils behind in the rocks too, but most of our information comes from microscopic pollen grains those pesky things that give us hay fever. Each plant species had its own distinctive-looking pollen grain. By grinding up rock samples and dissolving them with strong acid, paleontologists can extract the pollen grains and study them under the microscope. They can be compared with living species and identified, giving us a good idea of what plants were around when the dinosaurs lived. In parts of Alberta, especially around Drumheller, conditions were just right for the bones of the dinosaurs to be preserved after they died.
Excellent preservation requires rapid burial, otherwise the bones are soon broken up by scavengers.
There were lots of dinosaurs living around Drumheller 75 million years ago, and lots of rivers. If a dinosaur drowned crossing a river, its body would sink and become covered up by silt. The person who gets to name a new type of dinosaur or any other kind of animal or plant is the first person to write a description of the new specimen, showing how it is different from others like it. There is a set of rules for how the description is to be written, and how the names are to be composed. For example, there has to be a drawing or photograph of the new dinosaur, and the name has to have two parts.