Our planet came into existence about 4.6 billion years ago as a sea of molten rock. Life on earth began about 3.8 billion years ago and then through a process known as evolution driven by natural selection became the great diversity of plants and animals that we see today.
In his book The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design, Richard Dawkins writes:
“Paleontology is the study of fossils. It is a very important branch of biology, because evolutionary ancestors all died long ago and fossils provide us with our only direct evidence of the mammals and plants of the distant past. If we want to know what our evolutionary ancestors looked like, fossils are our main hope.”
The people who study ancient life forms and their evolution are known as paleontologists. According to a display at the Raymond M. Alf Museum of Paleontology:
“Paleontologists are scientists who reconstruct the past based on fossil and geologic evidence. They explore biological, ecological, and geologic change to understand how our present-day world came to be. Our understanding of fossils and the history of life is always being expanded and revised in light of new specimens and research findings.”
Fossils are simply the preserved remains or traces of ancient plants and animals. With regard to animals, the parts of the animal most likely to fossilize are the hardest parts, that is, bones, teeth, and shells. Frequently fossilization involves a process known as mineralization in which the bones of the animal are replaced over time to form rock.
One of the first steps in paleontology is to find a site, a place that is likely to contain fossils. Then, like archaeology, paleontology involves digging. Digging may involve a backhoe, but most often it is just hard work using picks, shovels, paint brushes, dental picks, chisels, and other implements to get to the fossils.
The San Bernardino County Museum in Redlands, California, includes an example of a paleontological site. According the display:
“An ideal fossil-making site is a stream bed. Streams are constantly on the move, carrying their sediment load with them. In stream settings, skeletons are disarticulated (taken apart) and carried downstream by the current. When the stream slows, it dumps its sediment over and around plant and animal remains on the stream bank. The trick to being preserved is to get covered up right away.”
In uncovering fossils paleontologists may find:
Articulated skeletons: in this instance, the skeleton is still joined together. While an articulated skeleton may be complete, in most cases some pieces, particularly the smaller bones, may be missing.
Associated skeletons: in this instance, the bones are spread out and may be broken. Working carefully, with an understanding of the animal’s anatomy, the paleontologist has to identify the different bones and their fragments and determine if they belong to one animal or several.
Isolated bones: often isolated bones are large bones, such as those in the leg or perhaps a skull.
Float: these are fossilized scraps of bone and often are too small to yield useful information.
Shown below are photographs of the paleontological site display at the San Bernardino County Museum.
Paleontology
Paleontology is the study of the ancient past through fossils. More from this series:
Paleontology 101: Ancient Cats (Photo Diary)
Paleontology 101: The Birds of La Brea (Photo Diary)
Paleontology 101: Wolves, Dogs, Cats, and Bears (Photo Diary)
Paleontology 101: Dinosaur Hall (Photo Diary)
Paleontology 101: The Mesozoic--The Age of Dinosaurs (Photo Diary)
Paleontology 101: The Cenozoic--The Age of Mammals (Photo Diary)