tritosternum
Tritosternum is a term primarily used in entomology to describe a specific anatomical feature found in insects. It refers to the third sternum, or ventral plate, of the thorax. The thorax itself is divided into three segments: the prothorax, mesothorax, and metathorax. Each of these segments has a dorsal plate (tergum) and a ventral plate (sternum). Therefore, the tritosternum is the sternum of the metathorax, which is the posterior-most thoracic segment.
The structure and prominence of the tritosternum can vary significantly among different insect species and orders.