What is Paleontology?

A branch of science concerning the scientific study of life from ancient times is known as paleontology. The scientists working on paleontology are known as paleontologists. Paleontologists collect the fossils of organisms from ancient times to classify them. The paleontologists also study the environment from ancient times to study the interactions between different organisms.

What is meant by fossils?

Any trace remains that are preserved or impressions of organisms from ancient times are known as fossils. Examples of fossils include the bones and skeletons of dinosaurs displayed in museums, the impression of animals, plants, or microbes on stones, and the preserved parts in oil, hair, DNA, and coal.

Types of fossils

There are various types of fossils.

• Index fossils help detect the geological period by examining the collection of sediments.
• Trace fossils help study animal behavior by examining the collection of traces, including tracks, fossilized feces, burrows, or feeding marks.
• Transitional fossils are the remains of organisms that have proved to be the connecting links between the ancient group of organisms and their descendants. They display the characteristics that are common in both groups.
• Microfossils help study climates from ancient times. The microfossils are made up of small organisms or some parts of the organisms.
• The resin that plants produced in ancient times became fossilized to produce amber. Ambers can have impressions or preserved remains of other organisms like microbes, insects, and animals.
• Reworked fossils form by erosion after organisms have been fossilized for quite some time. The fossil gets free from the rocks due to corrosion.
• Fossil wood is the fossilized form of the wood of a tree as wood can be easily preserved.
• Subfossils are those remains that have not been fossilized completely. They contain organic components that are useful in understanding the environment of the habitat of an organism.
• The chemicals and the fossilized fuels found in the earth are known as chemical fossils. These provide an understanding of the organic components found in historical life.

History of Paleontology

• Fossils have been in use throughout human history. Humans first used them as decorative items. In the middle ages, until the early 18^th century, fossils were considered mythological creatures. Some scientists interpreted that fossils were the remains of organisms, and therefore, used them in their research.
• Paleontology officially started in the 18th century (age of enlightenment). The fossils were classified, and the scientists understood that the accumulation of sediments for a long time formed the layers of rocks. 
• William Smith and Georges Cuvier discovered the field of paleontology in the early 19th century. They discovered that they could examine the layers of rocks using the fossils. In the late 19th century, the research of Charles Lyell found that similar types of fossils in one layer of rocks help in the formation of sequencing that can help identify the relationships between the same types of rock layers in different regions.
• Charles Darwin also studied a similar type of evolution of the living organisms in that period, suggesting the relationship between the ancient organisms and the present organisms. This research allows paleontologists to understand fossils based on the study of living organisms.

Subdivisions of Paleontology

The field of paleontology is divided into subdivisions based on the types of fossils used to study the different aspects of the earth, such as their environment or climate.

Vertebrate Paleontology

Vertebrate paleontology involves the study of vertebrates. The vertebrates are the animals containing vertebrae that form their backbones. Examples of vertebrates include:

• Fishes
• Birds
• Reptiles like lizards, dinosaurs, and crocodile
• Mammals like cats, dogs, and cows

The paleontologists examine the collection of the fossils of animals such as dinosaurs to construct their skeletons. Museums showcase these skeletons. For example, the paleontologists constructed the skeleton of the pterosaurs using lightweight bones that were hollow by examining the collection of their fossils. The study of their fossils suggested that the pterosaurs flapped their wings to fly. 

Invertebrate Paleontology

Invertebrate paleontology involves the study of invertebrates. Invertebrates are animals that do not contain vertebrae. Therefore, invertebrates do not have backbones. Examples of invertebrates include:

• Insects
• Corals 
• Worms
• Crabs 
• Spiders
• Shrimps
• Sponges

Bones do not form the fossils of invertebrates as they do not have bones. The invertebrates are studied using the impressions of the soft parts of their bodies. The paleontologists also study the tracks left on the ground or the ocean floor by the movement of invertebrates.

Invertebrate paleontology is also used to study the aquatic environment of ancient times. For example, the fossils of aquatic organisms found in the desert area suggest the presence of water instead of desert in ancient times.

Paleobotany

The study of the plants of ancient times is called paleobotany. The fossils used in paleobotany include the preserved parts of the plants, such as leaves, woods, and seeds, or the impressions left by the plants on the surfaces of rocks. Paleobotany is used to understand the evolution and the exponential diversity of plants. The subdivisions of paleontology where plant fossils are in use include:

• Paleoecology, where the research on the environments of ancient times takes place.
• Paleoclimatology, where the research on the climates of ancient times take place.

The presence of plant fossils in an area can help identify the climatic conditions and environment of that area in ancient times. The decomposition of plants can result in the formation of coal. The coal balls, found near coal mines, contain the fossils of the plants and help classify the plants responsible for the formation of coal. 

Micropaleontology

The microscopic organisms from ancient times are studied using micropaleontology. Examples include pollen, algae, protozoan, and small crustaceans. The microscopic organisms tend to have a very short life span, and they are also abundant. They form microfossils that cannot be seen with naked eyes. Instead, they are visualized with a microscope. 

Micropaleontology is used to identify the age of the layers of rocks as the microfossils tend to remain where they were found. Micropaleontology is also used to understand the ancient environment by examining the chemical composition of the microfossils.

Shells are formed by the components of the ocean water, which are left on the floor of the ocean after the death of organisms. Paleontologists study these shells to understand the evolution of the climate in the ocean. The paleontologists can also research the number of chemical components and nutrients present in the ocean in ancient times by examining the composition of the shell.

What is the significance of Paleontology?

• Paleontology is used to study the evolution of different organisms, environments, and climates.
• The science of paleontology provides the connection between the life, environment, and climate of the past with the life, environment, and climate of the present.
• The science of paleontology has identified various organisms that have become extinct in the course of evolution. 
• Paleontology connects geology with biology to understand the particular living locations of organisms.
• The science of paleontology also helps in the identification of the relationship between different geological places that are separated from each other by studying the similar fossils present in the rock layers.
• Paleontologists have created various skeletons of the ancient organisms that are showcased in museums. These museums provide knowledge of extinct organisms.

Common mistakes 

The students may assume that paleontology is only the study of fossils, which is not the case. Paleontology is used to study the life, climate, and environment of ancient times. 

Students may also assume that the skeletons of dinosaurs showcased in the museums are fossils found by paleontologists. However, paleontologists prepare the skeletons in museums after examining different fossils of the organism. 

Context and Applications

This topic is significant for undergraduate, graduate, and postgraduate courses, especially for:

• Bachelor of Science Paleontology
• Master of Science in Paleontology
• Doctorate in Paleontology

Related Concepts

• Evolution
• Ecology
• Diversity of Organisms

Practice Problems

Q1: Which of the following fields are connected by paleontology?

(a) Chemistry with biology

(b) Geology with biology

(c) Physics with biology

(d) Physics with chemistry

Correct Choice: (b)

Q2: Which of the following is used to study paleontology?

(a) Microbes

(b) Cellular organelles

(c) Fossils

(d) All of the above.

Correct Choice: (c)

Q3: What is meant by the term paleontology? Choose the correct option.

(a) The study of old creatures.

(b) The study of planets.

(c) The study of plants.

(d) None of the above.

Correct Choice: (a)

Q4: Who discovered paleontology? Choose the correct option.

(a) William Smith

(b) Georges Cuvier

(c) Both (a) and (b)

(d) None of the above.

Correct Choice: (c)

Q5: Which of the following is the subdivision of paleontology?

(a) Paleoecology

(b) Micropaleontology

(c) Paleoclimatology

(d) All of the above.

Correct Choice: (d)