NUMMATA (noun):
Plural form of "nummatum," a term derived from the Latin word "nummus," meaning coin, and commonly used in the field of entomology to describe small, platelike structures found on the exoskeleton of certain arthropods, particularly insects. Nummata are characterized by their circular or oval shape and are often raised or slightly convex, resembling miniature coins or tokens. They can be found across various regions of the insect's body, but are commonly observed on the thorax and abdomen.
Nummata serve various biological functions in arthropods. Primarily, they act as protective shields, providing a layer of defense to the underlying tissues from mechanical injuries, predators, and environmental stresses. Furthermore, nummata may assist in moisture retention by reducing water loss from the body surface, especially in arid habitats. Additionally, due to their conspicuous and distinctive appearance, nummata may have a role in species recognition, communication, or mating behavior, although research in these areas is not yet definitive.
The number, position, and morphology of nummata can vary greatly across different insect species, making them useful for taxonomic identification and classification. Their size, coloration, and patterns may also be subject to interspecific variation or sexual dimorphism. As a result, nummata have become important anatomical features studied by entomologists to gain insights into the evolutionary relationships, ecological adaptations, and behavior of various arthropod groups.
