Humans were an intelligent mammalian species that arguably originated on Coruscant. They gave birth to live young. They were bipedal beings with a bilateral symmetry, having a front and a back end, as well as an upside and downside. Their bodies were comprised of a torso with a head and four limbs attached to it. The upper limbs, or arms, ended in hands which had five fingers each; the lower ones, called legs, ended in feet. The human fingers had multiple points of articulation, and one of them was an opposable thumb that allowed for fine manipulation. Finally, they had one head perched atop their torso. Many other species, including the Twi'leks, the Mon Calamari, or the Zygerrians, were referred to as "humanoids" because of their structural resemblance to humans. Like many other species, humans needed to take in oxygen from their environment to live.