Evolution
The cranial vault is composed of the endocranium forming the basal parts, topped by the skull roof in land vertebrates.
In fishes no distinct cranial vault as such exists, the skull being composed of loosely jointed bones. The cranial vault as a distinct unit arose with the fusion of the skull roof and the endocranium on the early Labyrinthodonts. In amphibians and reptiles the vault is rather small and inconspicuous, only forming proper vaults in mammals and birds.
Read more about this topic: Cranial Vault
Famous quotes containing the word evolution:
“The evolution of sense is, in a sense, the evolution of nonsense.”
—Vladimir Nabokov (1899–1977)
“The more specific idea of evolution now reached is—a change from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity, accompanying the dissipation of motion and integration of matter.”
—Herbert Spencer (1820–1903)
“By contrast with history, evolution is an unconscious process. Another, and perhaps a better way of putting it would be to say that evolution is a natural process, history a human one.... Insofar as we treat man as a part of nature—for instance in a biological survey of evolution—we are precisely not treating him as a historical being. As a historically developing being, he is set over against nature, both as a knower and as a doer.”
—Owen Barfield (b. 1898)