The scientists who study fossils are called paleontologists. Paleontology is the field dedicated to the scientific study of ancient life, relying primarily on evidence preserved in the Earth’s crust. This discipline provides the most extensive record of the planet’s biological history, allowing researchers to reconstruct the evolutionary trajectory of life and understand past environments over vast spans of geologic time.
Paleontology: The Study of Ancient Life
Paleontology is defined by its subject matter: the fossil. A fossil is any preserved remain, impression, or trace of a once-living organism from a past geological age, typically considered older than 10,000 years. These remnants are most often found in sedimentary rock layers, which form when sand, mud, or silt compacts over time. Preservation usually requires the organism to be buried rapidly after death, preventing decay and scavenging.
While the most recognizable fossils are dinosaur bones, the term encompasses a much wider range of evidence. Body fossils include hard parts like petrified wood, mollusk shells, and vertebrate teeth, which become mineralized over millions of years. Other forms, known as trace fossils, offer insight into an organism’s behavior, such as preserved footprints, burrows, and fossilized waste known as coprolites. Paleontologists also study microscopic fossils, including ancient pollen grains, which provide rich data on past climates and ecosystems.
The Paleontologist’s Process
The work of a paleontologist begins with fieldwork, involving prospecting potential sites using geological maps and satellite imagery to identify rock formations known for fossil preservation. Once a site is located, the process shifts to meticulous excavation, where researchers carefully remove the surrounding rock matrix using specialized tools like small chisels and brushes. Large, fragile specimens are stabilized in the field by encasing them in a protective plaster jacket, allowing for safe transport to the laboratory.
Back in the lab, the preparation phase begins, where the fossil is painstakingly freed from its surrounding rock. Technicians use tools ranging from air scribes and small drills to chemical baths, depending on the rock’s hardness and the fossil’s delicacy. Fragile specimens are often consolidated with special glues to stabilize and repair breaks. Once fully prepared, the fossil moves into the analysis phase, utilizing a multidisciplinary approach that blends biology and geology.
Analysis involves techniques like radiometric dating to determine the absolute age of the fossil and the surrounding rock layers. Researchers use advanced imaging, such as CT scanning, to visualize internal structures without damaging the specimen, and 3D modeling to reconstruct the organism’s anatomy. By studying the fossil’s morphology and comparing it with other species, paleontologists interpret evolutionary relationships, reconstruct ancient ecosystems, and understand how the organism interacted with its environment.
Distinguishing Paleontology from Archaeology
The general public frequently conflates paleontology with archaeology, but the two disciplines are separated by their core subject matter and time frames. Paleontology focuses exclusively on ancient life forms, studying the fossils of plants, animals, and microorganisms across all of geologic time.
Archaeology, conversely, is a sub-discipline of anthropology concerned with human history and prehistory. Archaeologists study the material remains of past human cultures, including artifacts like pottery, tools, and ancient architecture. While paleoanthropology bridges both sciences by studying ancient human fossils, general archaeology focuses on the last few million years, seeking to understand human behavior and cultural development.
Major Fields of Specialization
Paleontology is a broad science with many sub-disciplines, each focusing on a specific type of organism or aspect of preservation.
Vertebrate Paleontology
This is the study of fossilized animals with backbones, including iconic groups like dinosaurs, ancient fish, and prehistoric mammals. Specialists reconstruct the skeletons of large animals and analyze their biomechanics to understand movement and feeding habits.
Invertebrate Paleontology
This field focuses on the fossilized remains of animals without backbones, such as ammonites, corals, and ancient insects. Invertebrates make up the vast majority of the fossil record and are often used in biostratigraphy to date rock layers.
Paleobotany
Paleobotany is the study of ancient plants, including leaves, stems, and spores. This provides data on the evolution of flora and the composition of ancient terrestrial environments.
Micropaleontology
This involves the study of fossils too small to be examined without a microscope, such as foraminifera and radiolarians. These tiny remains are often abundant in sedimentary rocks and are useful in the petroleum industry for dating rock strata and locating potential oil and gas reserves.