Classification of organisms on the basis of fossils record that play important role in elucidation of evolutionary relationships is

Options

A. Earliest systems
B. Phylogenetic systems
C. Morphotaxonomy
D. Artificial system

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the classification of organisms based on fossil records that help in understanding evolutionary relationships.

2. **Types of Classification Systems**: There are four main types of classification systems:
- **Practical Classification**: Based on the practical use of organisms.
- **Artificial Classification**: Based on one or two morphological characteristics.
- **Natural Classification**: This is further divided into:
- **Natural Formal Classification**: Based solely on morphological characteristics.
- **Natural Phylogenetic Classification**: Based on complete morphology and phylogeny (the evolutionary relationships of organisms).

3. **Role of Fossil Records**: Fossil records provide crucial information about the evolutionary history and relationships (phylogeny) of organisms.

4. **Identifying the Correct Classification**:
- The question specifically seeks the classification system that utilizes fossil records to elucidate evolutionary relationships.
- Since natural phylogenetic classification incorporates both morphology and phylogeny, it is the classification that uses fossil records effectively.

5. **Evaluating the Options**:
- **Practical Classification**: Not based on fossils.
- **Phylogenetic System**: Correct answer, as it uses fossil records to understand evolutionary relationships.
- **Morphotaxonomy**: Another name for natural classification, but it does not specifically focus on fossils.
- **Artificial System**: Not based on fossils.

6. **Final Answer**: The classification system that uses fossil records to elucidate evolutionary relationships is the **Phylogenetic System**.