A scholiast, quoting the fifth-century BC historian Hellanicus, tells us that, in addition to the Hesiodic Cyclopes (whom the scholiast describes as "the gods themselves"), and the Homeric Cyclopes, there was a third group of Cyclopes: the builders of the walls of Mycenae. Hesiodic Cyclopes
Hesiod, in the Theogony (c. 700 BC), described three Cyclopes: Brontes, Steropes, and Arges, who were the sons of Uranus (Sky) and Gaia (Earth), and the brothers of the Titans and Hundred-Handers, and who had a single eye set in the middle of their foreheads. They made for Zeus his all-powerful thunderbolt, and in so doing, the Cyclopes played a key role in the Greek succession myth, which told how the Titan Cronus overthrew his father Uranus, and how in turn Zeus overthrew Cronus and his fellow Titans, and how Zeus was eventually established as the final and permanent ruler of the cosmos. The names that Hesiod gives them: Arges (Bright), Brontes (Thunder), and Steropes (Lightning), reflect their fundamental role as thunderbolt makers. As early as the late seventh-century BC, the Cyclopes could be used by the Spartan poet Tyrtaeus to epitomize extraordinary size and strength.According to the accounts of Hesiod and mythographer Apollodorus, the Cyclopes had been imprisoned by their father Uranus. Zeus later freed the Cyclopes, and they repaid him by giving him the thunderbolt. The Cyclopes provided for Hesiod, and other theogony-writers, a convenient source of heavenly weaponry, since the smith-god Hephaestus—who would eventually take over that role—had not yet been born.
There are also coronal clefts mainly in skeletal dysplasias such as chondrodysplasia punctata. In dogs, butterfly vertebrae occur most often in Bulldogs, Pugs, and Boston Terriers. Transitional vertebrae
Transitional vertebrae have the characteristics of two types of vertebra. The condition usually involves the vertebral arch or transverse processes. It occurs at the cervicothoracic, thoracolumbar, or lumbosacral junction. For instance, the transverse process of the last cervical vertebra may resemble a rib. A transitional vertebra at the lumbosacral junction can cause arthritis, disk changes, or thecal sac compression. Back pain associated with lumbosacral transitional vertebrae (LSTV) is known as Bertolottis syndrome. One study found that male German Shepherd Dogs with a lumbosacral transitional vertebra are at greater risk for cauda equina syndrome, which can cause rear limb weakness and incontinence.The significance of transitional vertebrae has been questioned by one study finding similar prevalence in the general population as those with low back pain,  but more recent study found a large difference. Spina bifida
Spina bifida is characterized by a midline cleft in the vertebral arch. It usually causes no symptoms in dogs. It is seen most commonly in Bulldogs and Manx cats. In Manx it accompanies a condition known as sacrocaudal dysgenesis that gives these cats their characteristic tailless or stumpy tail appearance. It is inherited in Manx as an autosomal dominant trait.