Snakes are misunderstood and often maligned, primarily out of ignorance about their true nature and position in the natural world. The oldest known fossil snake, Eophis underwoodi, was a small snake that lived in southern England about 167 million years ago. Snakes are thought to have evolved from terrestrial lizards as early as the Middle Jurassic Epoch (174.1 million to 163.5 million years ago). However, snakes possess increased numbers of vertebrae and have developed two novelties among vertebrates: a tracheal lung in the neck region and a venom-conducting system for subduing prey. The visceral organs are elongated, with reduction of the left member in relation to the right the left lung is greatly reduced or even lost entirely. Internally, they have lost the urinary bladder. Unlike lizards, snakes lack movable eyelids, which results in a continuous and often disconcerting stare. Certain burrowing lizards may have only front or hind limbs or be completely legless. All snakes lack external limbs, but not all legless reptiles are snakes. Classified with lizards in the order Squamata, snakes represent a lizard that, over the course of evolution, has undergone structural reduction, simplification, and loss as well as specialization. Snake, (suborder Serpentes), also called serpent, any of more than 3,400 species of reptiles distinguished by their limbless condition and greatly elongated body and tail. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.
Snake hides how to#
Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.
0 kommentar(er)
