Necks in The Animal Kingdom
The neck appears in some of the earliest of tetrapod fossils, and the functionality provided has led to its being retained in all land vertebrates as well as marine-adapted tetrapods such as turtles, seals, and penguins. Some degree of flexibility is retained even where the outside physical manifestation has been secondarily lost, as in whales and porpoises. A morphologically functioning neck also appears among insects. Its absence in fish and aquatic arthropods is notable, as many have life stations similar to a terrestrial or tetrapod counterpart, or could othewise make use of the added flexibility.
The word "neck" is sometimes used as a convenience to refer to the region behind the head in some snails, gastropod mollusks, even though there is no clear distinction between this area, the head area, and the rest of the body.
Read more about this topic: Neck
Famous quotes containing the words animal and/or kingdom:
“Be a good animal, true to your animal instincts.”
—D.H. (David Herbert)
“I suddenly realized that the devout Russian people no longer needed priests to pray them into heaven. On earth they were building a kingdom more bright than any heaven had to offer, and for which it was a glory to die.”
—John Reed (1887–1920)