Final answer:
The thoracic vertebrae are characterized by a heart-shaped body and costal facets, with a long spinous process and articulation sites for rib attachment.
Step-by-step explanation:
The type of vertebrae characterized by a heart-shaped body and costal facets is the thoracic vertebrae. The thoracic vertebrae have larger bodies than those of the cervical vertebrae, and a typical midthoracic vertebra has a distinctive long, downward projecting spinous process. In addition, these vertebrae possess articulation facets on the body and transverse processes for the attachment of ribs. Among the cervical, lumbar, and sacral, it is the thoracic vertebrae that display these characteristics and hence are the answer to this question.