Hara's Lab

Paleontology – the science which studies fossils
“Wow. That sounds great.” This is the typical first response from people, when I introduce my major to them. Then, they ask me again with some hesitation. “But, what is paleontology? What are you doing exactly?” After hearing a few words such as fossils, excavation, and field trips from me, some of them may pleasantly respond. “Oh, how splendid the relics are! History was my favorite class. How do you feel when you find the treasure?” Wrong. Some say like this. “Fossils! Dinosaurs! I know that! I was so fascinated with the movie ‘Jurassic Park’. Tell me please. Is that movie real? Can you revive the dinosaurs, too?” Only partly correct. As a paleontologist, I am not the Indiana Jones who seeks the hidden treasures, and am not the magician who can make a life from a single DNA, either. I am a just scientist who tries to reveal what the Earth and the life looked like in the past, which might trace back to several hundred million years ago. Of course, I live in the present, not in the past. How can I do that? By examining fossils, which the past leaves us for understanding that.

What is a fossil? One can simply say that a fossil is the stone having the dead plants or animal. As the origin of the word – came from fossilis, which means ‘dug up’ in Latin – implies, fossils are usually buried under ground and have to be excavated. However, that’s not enough. With that definition, one may insist that he found a fossil from his backyard, when he dug up the bone which his dog had buried before a few days. Unfortunately, that’s not a fossil. The bones from historic age, when human beings have developed civilization and have acted as a main component in the environments – that is the field of archaeologists or biologists – are not fossils. The fossil should belong to the geologic age, which means the time interval from the first formation of rocks in the Earth (about 3.8 billion years ago) to the appearance of mankind (about one million years ago). The temporal boundary between the historic age and the geologic age, however, is not unequivocal but debatable. Thus one can use the word fossil to refer the ‘prehistoric’ life, such as hominid fossils, conventionally. In addition to temporal statement, fossils need another explanation on their physical characteristics to be defined exactly. Not only bones, but any remains from the ancient life may belong to fossils as long as they were made of or by the ancient lives, such as leaves, skins, feathers, burrowing holes, foot prints, and even droppings from the animals. Including these discussions, the glossary of geology defines a fossil as any remains, trace, or imprint of a plant or animal that has been preserved in the Earth’s crust since some past geologic or prehistoric time.

The branch of science dealt with these fossils is paleontology, originated from paleo – (from Greek palaios ‘ancient’), onta (from Greek ‘beings’), and –logy (from Greek – logia ‘subject of study’). Paleontology studies the fossils – the life remained on the stone, which means paleontologists have to be aware of both the life and the stone. Thus paleontology is located between biology and geology. Geology tells the characteristic of the fossil-bearing rocks such as sedimentary environment, paleoclimate and paleogeography. Biology helps to interpreting the life habit and the characteristics of the extinct lives by comparing with the present life forms. After researching fossils with that information, paleontologists can also help geologists to solve when and where the rock is formed, and help biologists to solve how the present lives have been evolved from the primitive ones.

Then, what do paleontologists do with fossils exactly? Paleontologists are detectives and crime scene investigators, who deal the cases about the past. What do detectives do when homicide happens? They run into the crime scene, watch the bodies carefully, gather evidences, bring those back into their office, identify the victim, guess the time of death, reveal the cause of the death, analyze the fingerprints, search the database on the criminals, set possible suspects, decide who the killer is, and finally write a report on the case. Paleontologists do the same. They have field trips where fossils occur, watch rocks and fossils carefully, gather fossils and rock specimens, bring those back into their laboratory, identify the name and the biological category of the fossil, guess which age the fossils belong to, reconstruct the environment where the lives inhabited, analyze the samples in various ways, search the academic papers on those fossils, set possible models which explain what looked like in the past, and finally write a paper on the fossils.

For example, I have studied the trilobite – the extinct animal, which was abundant in the sea about four hundred million years ago, and which resembles the horseshoe crab – fossils in the Mt. Taebaek, Korea. From my knowledge on geology, I already knew that the fossil-bearing rock is limestone, which indicates those stones were formed in the warm and shallow sea. During field trips, I examined the rock strata, which is about two hundred meter thick, found fossils within rocks, and excavated numerous fossils to bring those back to my laboratory for further research. In the laboratory, I prepared the fossils in detail, took photos, and identified the name of trilobites by using references. As a result, over ten species of trilobites were newly reported from the Mt. Taebaek. Those trilobites are about 430 million years old, and have close affinity with the trilobites of north China rather than with those of America and Europe at that time, which means that Korea and north China were very close geographically several hundred million years ago and that those regions are covered with shallow and warm seas. Now I’m writing the paper on the trilobites from the Mt. Taebaek.

Do you wonder what I am doing in paleontology? Here’s the answer. I am watching the Earth and the life in the past through fossils in the present.