Here's why:

* Block-like body: Lumbar vertebrae have large, thick, and block-shaped bodies compared to other vertebral regions. This is because they bear the most weight of the upper body.

* Short, stout spinous process: Lumbar vertebrae have short and thick spinous processes that point almost directly backward. This contributes to their overall strength and helps protect the spinal cord.

While other vertebrae like the thoracic vertebrae also have short spinous processes, their bodies are not as block-like as those of the lumbar vertebrae.

Note: It's always important to consider the context when identifying vertebrae. A detailed description of the vertebral features, as well as its position in the vertebral column, is essential for accurate identification.