Exoskeleton

An exoskeleton is a hard, supportive and/or protective structure that occurs in the external anatomy of many organisms. Most commonly found in invertebrates, such as insects and other arthropods, exoskeletons are also found on some sentient lifeforms.

Tholians possessed exoskeletons composed primarily of minerals, and were susceptible to cracking or even shattering at temperatures that were lower than their natural tolerances. (ENT: "In a Mirror, Darkly")

Rasiinians feature a bony exoskeletal plate that covers their faces.

Klingons have an exoskeleton that encases their cranium. This protective structure has a feature called the tricipital lobe. (TNG: "Descent")

Although Klingons are stated to possess a cranial exoskeleton, it seems apparent that this structure is not outside of their skin like a typical exoskeleton would be. This may indicate that a Klingon's cranium actually features two distinct layers of bone, and "exoskeleton" is used to distinguish the outer layer, which is likely where their well-known cranial ridges are found. This would offer extra protection to the brain (except at the vulnerable tricipital lobe), and seems to fit in very well with the Klingon principle of Brak'lul.

Borg drones are fitted with artificial exoskeletons known as exo-plating. This protective layer is sometimes installed directly over the clothing and equipment that the drone had been wearing when it was assimilated. (Star Trek: First Contact) The Borg exoskeleton in Seven of Nine's arm was capable of withstanding five million gigawatts of power. (VOY: "Revulsion")

External link

• Exoskeleton at Wikipedia