Lithosphere 50–140 km thick (but beneath the mid-ocean ridges is no thicker than the crust), while continental lithosphere has a range in thickness from about 40 km to perhaps 280 km; the upper ~30 to ~50 km of typical continental lithosphere is crust. The mantle part of the lithosphere consists largely of peridotite. The crust is distinguished from the upper mantle by the change in chemical composition that takes place at the Moho discontinuity. Oceanic lithosphere consists mainly of mafic crust and ultramafic mantle (peridotite) and is denser than continental lithosphere, for which the mantle is associated with crust made of
Common name not always English. For example, "Dikkop" is the centuries-old South African vernacular name for their two local species: "Burhinus capensis" is the Cape dikkop (or "gewone dikkop", not to mention the presumably much older Zulu name "umBangaqhwa"); "Burhinus vermiculatus" is the "water dikkop". The thick joints in question are not even, in fact, the birds’ knees, but the intertarsal joints—in lay terms the ankles. Furthermore, not all species in the genus have “thick knees”, so the thickness of the "knees" of some species is not of clearly descriptive significance. The family Burhinidae has members that have various common names even