Centrum of vertebrate in mammals:-

Options

A. Amphicoelus
B. Procoelus
C. Opisthocoelus
D. Acoelous

Answer

To answer the question about the centrum of vertebrae in mammals, we will analyze the options provided and determine which one is correct.

### Step-by-Step Solution:

1. **Understanding the Centrum**: The centrum is the central part of a vertebra. It plays a crucial role in supporting the vertebral column and providing attachment points for muscles and ligaments.

2. **Evaluating the Options**:
- **Option 1: Amphicilus**: This type of centrum is bi-concave, meaning both the anterior and posterior surfaces are concave. This is not characteristic of mammalian vertebrae.
- **Option 2: Procellus**: This type has a concave cranial (front) surface. This is not typical for mammals, as their vertebrae do not generally have this structure.
- **Option 3: Opisthocellus**: In this type, the vertebra is concave at the posterior (back) surface. Again, this does not describe the typical mammalian vertebrae.
- **Option 4: Osceolus**: This type of centrum is characterized by a more cylindrical shape, which is the correct description for the vertebrae found in mammals.

3. **Conclusion**: After evaluating all the options, the correct answer is **Option 4: Osceolus**. This is the type of centrum found in the vertebrae of mammals.