Spotted Python Antaresia maculosa Scientific classification Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Sauropsida Subclass: Diapsida Infraclass: Lepidosauromorpha Superorder: Lepidosauria Order: Squamata Suborder: Serpentes Linnaeus, 1758 Infraorders and Families Alethinophidia  Nopcsa, 1923 Acrochordidae  Bonaparte, 1831 Aniliidae  Stejneger, 1907 Anomochilidae  Cundall, Wallach & Rossman, 1993 Atractaspididae  Günther, 1858 Boidae  Gray, 1825 Bolyeriidae  Hoffstetter, 1946 Colubridae  Oppel, 1811 Cylindrophiidae  Fitzinger, 1843 Elapidae  F. Boie, 1827 Loxocemidae  Cope, 1861 Pythonidae  Fitzinger, 1826 Tropidophiidae  Brongersma, 1951 Uropeltidae  Müller, 1832 Viperidae  Oppel, 1811 Xenopeltidae  Bonaparte, 1845 Scolecophidia  Cope, 1864 Anomalepididae  Taylor, 1939 Leptotyphlopidae  Stejneger, 1892 Typhlopidae  Merrem, 1820 A snake is an elongate reptile of the suborder Serpentes. Like all reptiles, snakes are covered in scales. All snakes are carnivorous and can be distinguished from legless lizards by their lack of eyelids, limbs, external ears, and vestiges of forelimbs. The 2,700+ species of snakes spread across every continent except Antarctica ranging in size from the tiny, 10 cm long thread snake to pythons and anacondas at 9 m (30 ft) long. In order to accommodate snakes' narrow bodies, paired organs (such as kidneys) appear one in front of the other instead of side by side. While venomous snakes comprise a minority of the species, some possess potent venom capable of causing painful injury or death to humans. However, venom in snakes is primarily for killing and subduing prey rather than for self-defense. Snakes may have evolved from a lizard which adapted to burrowing during the Cretaceous period (c 150 Ma), though some scientists have postulated an aquatic origin. The diversity of modern snakes appeared during the Paleocene period (c 66 to 56 Ma). A literary word for snake is serpent (a Middle English word which comes from Old French, and ultimately from *serp-, "to creep"[1], also µÁÀÉ in Greek). The serpent is also a symbol of the healing arts.