Starting from the 18th century, the concept of paleontology was established, which was further developed in the 19th century. Paleontology is the study of prehistoric life, including the evolution of organisms and the interactions with each other and with the environment around them. It is also the study of fossil remains from past geological periods and the relationships between ancient and modern species. Although it is a field of biology, it has also been associated with geology because of the attempt to learn about the Earth itself, not just its organisms. This field seeks to explain causes rather than observe effects by conducting experiments. The use of paleontology was and still is an extremely important aspect of identifying organisms from the Paleozoic era, a period of time in which extinction and evolution collided with each other, helping to shape the biological world we know today. The Paleozoic era began approximately 542 million years ago. years ago and lasted about 291 million years. It was divided into six parts known as the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The oldest subdivision of the Paleozoic era was the Cambrian period, which is also important for paleontologists because the rocks of this period are rich in fossils. During this period, evolution reached its peak and for approximately 40 million years animal body plans changed rapidly (Williams et al, 2007). Because of the sudden explosion of diversity during this period, it is sometimes called the Cambrian radiation or Cambrian explosion. Many of the species that existed during this period were marine organisms, especially since at the beginning of the Cambrian period life was entirely confined to the oceans. Evolution during this time period is... middle of paper......ndred millions of years, the remains they left behind tell paleontologists today a lot about how they lived and how they adapted. With the understanding and ability to delve deeper into the meaning of a fossil, paleontologists can now attempt to unravel the unknown of past periods. The ability to examine a fossil using calcite remains and DNA has improved throughout history due to our technological advances and knowledge gained from past discoveries. Conclusions can finally be drawn and the existence of trilobites can be proven. What we know about trilobites today is published around the world, revealing their lifestyles, feeding and reproductive patterns, relatives to this species, and how they have managed to adapt to the environment around them. The mystery of the trilobite has finally filled a missing chapter in the novel of Earth's history.