Snakes are elongated, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with many more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads with their highly mobile jaws. To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca.


Dinilysia p1


Living snakes are found on every continent except Antarctica, in the Pacific and Indian Oceans, and on most smaller land masses — exceptions include some large islands, such as Ireland and New Zealand, and many small islands of the Atlantic and central Pacific. More than 20 families are currently recognized, comprising about 500 genera and about 3,400 species. They range in size from the tiny, 10 cm-long thread snake to the Reticulated python of up to 8.7 meters (29 ft) in length. The fossil species Titanoboa cerrejonensis was 15 meters (49 ft) long. Snakes are thought to have evolved from either burrowing or aquatic lizards during the mid-Cretaceous period, and the earliest known fossils date to around 112 MYA. The diversity of modern snakes appeared during the Paleocene period (c 66-56 MYA). The oldest preserved descriptions of snakes can be found in the Brooklyn Papyrus.

Most species are nonvenomous and those that have venom use it primarily to kill and subdue prey rather than for self-defense. Some possess venom potent enough to cause painful injury or death to humans. Nonvenomous snakes either swallow prey alive or kill by constriction.

In Walking with... seriesEdit

Walking with DinosaursEdit

Death of a Dynasty

There is a Dinilysia snake, featured in a cameo during the last episode of the series. It is harassed by Tyrannosaurus chicks and eventually retreats. It is played by a modern red-tailed boa.

Walking with Beasts Edit New Dawn Edit

A green snake is seen moving past a tree on the forest floor after the Giant Ant attack on the baby Gastornis


  • Mosasaurs, featured in Sea Monsters and Primeval, were related to snakes, though they retained their limbs.
  • Titanoboa, the snake featured in Primeval: New World, was Cenozoic's largest extinct reptile.
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