Sources : Uranoscopus

Isidore of Seville [7th century CE] (Etymologies, Book 12, 6:35): The uranoscopus is named from the eye that it has in its head, with which it is always looking upward. - [Barney, Lewis, et. al. translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Quadrupeds 4.108; Fish 7.32; 7.89): [Thomas describes the uranoscopus as both a quadruped and a fish. He also describes the uranoscopus under the name granus.] [Quadrupeds 4.108] Uranoscopus is an animal with a broad chest, small ears, an erect face, a protruding neck, having only one eye on the top of the head, which it always aims at the sky; whence the uranoscopus, as Huitius says, is called a wild ox from 'those who aim'. This animal is more intelligent than many animals, and this especially in its own keeping. [Fish 7.42] Granus is sea fish. As the philosopher says, contrary to the nature of all animals, it has one eye on the top of its head: with this eye it is always watching out for traps. Those are signified by this fish, whose eyes are always on the Lord, as with the mirror of divine contemplation, whatever adversities, whatever dangers may happen, are contemplated more clearly, so that they may have one single-minded eye on God, with which they may be seen before and behind. [Fish 7.89] The uranoscopus is a fish of the sea which is said to have one eye: for it has one eye at the top of its head, and this eye is so sharp of sight that no trap can escape its notice. But it signifies God himself, who with singular foresight and providence, whose eyes, brighter than the sun, contemplate good and evil. - [Badke translation/paraphrase]