notum
Notum is a term with multiple uses in biology. In arthropod anatomy, notum refers to the dorsal plate of a thoracic segment. The thorax typically comprises prothorax, mesothorax, and metathorax, with a notum on the dorsal surface of each segment. The notum serves as structural protection and as an attachment site for flight muscles in winged species; in some insects it can bear additional plates, such as the scutellum, and its size and shape can vary among species, contributing to comparative anatomy and evolution studies.
In molecular biology, Notum (capital N) denotes a secreted carboxylesterase enzyme encoded by the NOTUM gene
Etymology for both uses traces to Latin notum, meaning back or dorsum, reflecting the dorsal nature of
See also: Wnt signaling, tergite, sternite, scutellum, NOTUM gene.