Question

In mammals, the presence of odontoid process in the centrum is a characteristic of

• A. Atlas vertebra
• B. Axis vertebra
• C. Typical cervical vertebra
• D. Thoracic vertebra

Answer 1

The correct option is B Axis vertebra

The odontoid process, or dens, is a bony projection from the axis ($C_2$) upward into the ring of the atlas ($C_1$) at the top of the spine. During embryogenesis, the body of the odontoid is derived from the centrum of the atlas and separates from the atlas, fusing with the superior portion of the axis.

So, the correct answer is option B.