CLASSIFICATION OF ORGANISM IN PALEONTONLOGY

Organism classification is the process of organizing and categorizing organisms into different groups based 3.on their characteristics, evolutionary relationships, and genetic similarities. It involves the study of their relatedness and to provide a systematic framework for studying and understanding the diversity of life on Earth. There are three types of classification , are as follows: 

1. TAXONOMY
2. PHYLOGENY
3. PHENETIC OR TYPOMORPHIC

A. TAXONOMIC CLASSIFICATION:

A taxonomy (or taxonomical classification) is a scheme of classification, based on their morphological similarities or dissimilarities. In which organism are organized into groups or rank. These ranks, broad to specific, including kingdom, phylum, class, order, family, genus, and species.

1. Kingdom: The highest taxonomic rank, organisms are divided into distinct kingdoms based on their fundamental characteristics (Species)and organization. Examples include: Animalia (animals), Plantae (plants), Fungi (fungi), Protista (protists), or Monera (bacteria).
2. Phylum: Within each kingdom, organisms are further divided into different phyla based on their overall body plan and structural characteristics. For example, in the animal kingdom, phyla include Chordata (chordates), Arthropoda (arthropods), and Mollusca (mollusks).
3. Class: Phyla are further divided into classes based on more specific features and characteristics. For instance, within the phylum Chordata, classes include Mammalia (mammals), Reptilia (reptiles), and Aves (birds).
4. Order: Classes are subdivided into orders, which represent distinct groups of organisms with shared characteristics. Examples of orders include Carnivora (carnivores), Primates (primates), and Rodentia (rodents).
5. Family: Orders are further divided into families, which are smaller groups of organisms that share more specific characteristics. Families often end in the suffix "-idae." For example, within the order Primates, families include Hominidae (great apes and humans) and Cercopithecidae (Old World monkeys).
6. Genus: Families are divided into genera (singular: genus), which represent even more closely related groups of organisms. Genera are usually given a Latin or Greek name and are capitalized.  For example, within the family Hominidae, the genus Homo includes modern humans and their extinct relatives.
7. Species: The most specific level of classification or fundamental unit of taxonomic classification. A species consists of a group of individuals that share similar characteristics .Species names are typically composed of two parts: the genus name (capitalized) and the species name (lowercase). For example, Homo sapiens is the scientific name for modern humans.

B. PHYLOGENIC CLASSIFICATION:

Phylogenetic classification, also known as cladistic classification or phylogenetics, it is the groups of organisms that based on their evolutionary relationships.

The foundation of phylogenetic classification is the construction of phylogenetic trees or cladograms, which are “graphical representations” of the branching patterns of evolutionary relationships among organisms. These cladogram depict the sequence of branching events, showing the common ancestors and the divergence of lineages over time.

Phylogenetic classification is based on the principle of common descent, which suggests that all organisms share a common ancestor and have evolved through a process of descent with modification. Organisms that have more recent common ancestors are considered to be more closely related than those that show more distant ancestors.

Phylogenetic classification groups organisms into clades, which are monophyletic groups that include an ancestor and all its descendants. A monophyletic group consists of a common ancestor and all of its evolutionary descendants, capturing the idea of shared ancestry. For example,

                    A

                  /   \

                 B     C

                / \   / \

               D   E F   G

 

In this example, we have four organisms labeled A, B, C, and D, represented as branches in the cladogram. The cladogram illustrates their evolutionary relationships based on shared derived characteristics.

• Organisms A, B, and C share a common ancestor, represented by the base of the cladogram.
• Organism A diverged first and is the most ancestral.
• Organisms B and C diverged from A and form a more recent common ancestor.
• Organisms D, E, F, and G are descendants of the common ancestor of B and C.
• Organisms D and E are more closely related to each other than to F and G.

This cladogram provides a visual representation of the branching pattern and relationships among these organisms. It shows their evolutionary history and the sequence of divergence events. 

C. PHENETIC OR TYPOMORPHIC:

Phenetic or typomorphic classification is a method of classification based on the overall similarity of organisms, focusing on observable traits and characteristics rather than evolutionary relationships. It groups organisms together based on common similarities in their physical features, without considering their evolutionary history.

This classification, also known as morphological classification, is a method that emphasizes the importance of specific, characteristic morphological features or traits in classifying organisms. It focuses on identifying and categorizing organisms based on distinct and defining morphological characteristics. The emphasis is on the recognition and classification of unique and diagnostic features rather than overall similarity or evolutionary relationships.

Here's an example of phenetic or typomorphic classification based on a specific characteristic:

• Lophophore of brachiopoda
• Dentition pattern of bivalve

By organizing organisms into taxonomic ranks, taxonomic classification provides a standardized and organized system for categorizing and studying living organisms.

Phylogenetic classification provides a more objective and explicit framework for understanding the evolutionary relationships among organisms. It allows scientists to trace the history of traits, study patterns of evolution, and make predictions about evolutionary patterns and processes.

While taxonomy and phenetics are primarily concerned with categorizing organisms based on their observable traits, phylogeny takes into account the evolutionary history and genetic relationships between organisms. Phylogenetic classification provides a more comprehensive understanding of the evolutionary relationships and the pattern of descent among different groups of organisms.

It's important to note that phenetic or typomorphic classification is often less precise in reflecting true evolutionary relationships compared to phylogenetic classification, which considers genetic and evolutionary data. Phenetic classification is mainly used for practical purposes, such as field identification or initial categorization based on readily observable features.