A Biological Overview of Equus mannulus monoceros
A Physiological Study of Unicorn Ponies by Twilight Sparkle
As a unicorn, one might expect me to be biased towards my own race. As a researcher and a student of Princess Celestia, I can assert that I remain objective throughout this essay and others. The physiology of unicorns is largely unremarkable in comparison to other members of the Equus genus, and virtually unchanged in comparison to the evolutionary ancestor Equus ferus genesis, save for one feature: magic. Unicorns are remarkable among ponykind for their active magical ability, use of spellcasting and sorcery, and presence of a horn used for the manipulation of the magical aether as described in by Starswirl the Bearded in the Studium Magicae. Unicorns are defined by magic, which pervades across all aspects of their culture and physiology.
As stated above, the majority of Equus mannulus monoceros’ physiology is unremarkable. The skeletal system is neither as strong as that of an earth pony, nor as light as that of the pegasi. Similarly, the muscular system is less developed than the brawn earth ponies possess or the agile grace of pegasus physiology. Athletically, most unicorns can’t hope to compete with members of the other pony subspecies, as even with muscular training the cardio-respiratory systems of the unicorn are underdeveloped in comparison to the rest of ponykind. These drawbacks limit unicorns from many jobs requiring manual labor and as a result further emphasize their other talents.
Positioned atop the dorsal surface of the cranium is the defining structure of the unicorn. The Corneus Unus is a true horn, with a core of bone (Corneus Summa), surrounded by layers of keratin and protein. As the horn grows, the keratin and protein sheath develops along a spiral path along grooves in the Corneus Summa. This sheath carries pigment cells that assume the same color as the rest of the unicorn’s body, and differences in horn color are rare and may signify disease. The horn is very sturdy, and can heal from most non-magical injuries with no issues, allowing a unicorn to reliably use it for magical purposes.
Housed inside the Corneus Summa is the Corneus Nerve, a nerve that connects the horn directly to the Hippocampus and to the Magnus Gland, which translates synaptic messages into base spells for casting. Spellcasting takes an amount of exertion in direct correlation to the difficulty of the spell, with spells such as telekinesis becoming more difficult in relation to the mass, volume and range of the manipulated object. If a unicorn becomes practiced enough in magic, the exertion required for spellcasting lessens, and higher tier spells can be safely attempted. Magic proficiency varies between ponies, however, and much of it is based in the talents of the spellcaster.
The magical abilities of unicorns are far reaching, comprising the entire scientific branch of Thaumatology. Different schools of magic interpret unicorn spellcasting differently, but that is a matter for another essay. Unicorns are able to do much with their magic, with Pre-Classical examples of groups capable of moving the Sun and Moon. Such abilities have a high cost, however, as the caloric intake of a unicorn skyrockets with intense magic use. This required the Unicorn Kingdoms of the Pre-Classical Era to demand large amounts of food from the earth pony tribes under their control, a feudal system of serfdom that continued until the Great Migration in Equestria and until the Grand Revolution in Prance across the sea. The power held by unicorns influences their high-society culture even to this day.
Unicorns are known for the many noble houses in Canterlot and the many successful businessponies in Manehatten and beyond. With the abilities allotted to them by magic, many unicorns have pursued employment in manufacturing, engineering, and especially business jobs. This yields them higher incomes on average than pegasi or earth ponies, especially among the nobility. As Equestria industrializes, however, many of the old ways will soon be obsolete. Unicorns must adapt to the new world, or find that their power may perish with the last.