An estimated 55,000 amateur rock hounds belong to organized clubs in the United States, and an untold additional number with no formal group membership also delight in fossil hunting in areas open to the public. You should locate and join one of these clubs and/or take fossil-hunting expeditions and visits to museums on your own. Local museums with a strong geology component frequently conduct field trips that are open to the public.
The Midwest and Great Plains states are especially rich in fossil beds, owing to the inland sea that once overlay these areas and whose sediments protected the skeletal remains of creatures from predation or being moved about. Professional geology societies publish brochures on fossil hunting and the kinds of fossils available in different locales. State geological societies, often housed on the main campus of state universities, are excellent sources of information. Earthwatch Institute is an organization that involves people with various environmental projects, including the mammoth graveyard fossil excavation site in Hot Springs, South Dakota.
Paleontologists broadly classify themselves according to the life-form studied. Palynologists study tiny to submicroscopic life-forms, such as pollen or plankton. Microfossils may be of plant or animal origin and are extremely abundant. Paleobotanists study macroscopic fossil plants.
In the animal kingdom, vertebrate paleontologists study animals with a backbone, among them the classes of fishes, birds, reptiles, and mammals. Each area of specialization requires extensive knowledge of the anatomy, ecology, and habits of modern representatives of the class. Invertebrate paleontologists study animals without a backbone, such as the classes of insects, sponges, corals, and trilobites. Invertebrate paleontologists are especially useful to the oil industry, for fossil plankton taken from drilling cores are an indication of the age of the rocks and of the formations in which oil reservoirs are likely to be concentrated. The mining and minerals industry also hires stratigraphers and petrographers, who study the distribution and content of rock layers to identify subsurface mineral deposits. These scientists helped to discover rare quarries of limestone in Indiana and other areas. This limestone, composed of the skeletal remains of tiny fossilized creatures, has provided impressive amounts of building material. However, the mining and minerals industry has few positions for paleontologists.
When conducting paleontological research, scientists' analyses begin with careful measurement and anatomical description of fossils, accompanied, if possible, by drawings showing what the three-dimensional creatures may have looked like in life. The fossils then are dated and placed in a physical context. Dating may entail both laboratory analyses and comparisons with fossil beds of known age or a comparison with stratigraphic layers of rock in different formations around the world. In the third step, the fossils and the formations in which they occurred are used to construct a history of Earth on either a small, local scale or a large scale. Large-scale events that can be reconstructed from fossil evidence include the uplift, tilting, and erosion of mountain ranges, the rise and subsidence of seas, and movements of landmasses over geological time. In the fourth step, fossils are used as evidence of life to fill in missing links in the fossil record, to revise taxonomic classifications, and to construct the biology of descent of living organisms.
Museum curators are linked to the fourth phase of paleontological analysis, for virtually all contemporary geology curators are evolutionists. Museum curators typically hold a doctorate and have done considerable independent research; these positions are highly competitive. Geology curators must raise grant funding to support themselves and a work crew in the field, and some have teaching responsibilities in joint programs of study with universities as well. Collection managers in geology usually have a minimum of a master's degree; some have doctorates. Geology collection managers study, catalogue, and maintain the museum's collection, ship specimens to external researchers for study, and sometimes participate in fieldwork. Ordinarily there is one collection manager for the geology holdings, but occasionally there is more than one. In that case, the duties may be divided among vertebrate mammals, invertebrate mammals, fossil amphibians and reptiles, fossil birds, and fossil plants. Collection managers are generalists and work as colleagues with curators.
Some paleontologists work as college teachers. To teach at this level, they must have a doctorate or be a candidate for a doctorate. Their primary educational responsibilities are divided between teaching undergraduate courses in earth science and advanced seminars in paleontology. In addition to in-class duties, they must also prepare lessons and curriculum, prepare tests, meet with students during office hours, and attend department meetings. They also conduct personal research, focusing on any area of the field that interests them.
Although the preponderance of paleontological research is carried out on land, marine fossil beds are of great interest. The cost of mounting an expedition to extract samples of sedimentary rock from the deep-sea floor usually means that the sponsoring institution must procure sizable support from industry or the government. Some paleontologists work in the oil industry to develop offshore wells; a few find employment with oceanographic institutes.