SkullThe skull sits at the front of the backbone. Its jaw bones are only loosely joined to the braincase.
Body vertebraeThe vertebrae of the body. Each one carries a pair of ribs.
RibsA pair of long, curved ribs on each body vertebra. They are movable, and the tail has none.
Pelvic spursClaw-like remains of the hind legs, on each side of the vent. Pythons and boas have them; most snakes do not.
Tail vertebraeThe vertebrae of the tail. They carry no ribs.
Skull from the side 11
BraincaseA solid box of bone around the brain. The jaw bones hang loosely from it.
QuadrateThe strut that joins the lower jaw to the skull. It swings freely, which lets the mouth open very wide.
TeethSharp teeth that curve backward. They grip the prey while the jaws draw it in.
DentaryThe front bone of each half of the lower jaw. The two dentaries are joined at the chin only by a stretchy ligament.
MandibleThe lower jaw, which meets the quadrate at the jaw joint. Each half is made of several bones.
MaxillaThe main tooth-bearing bone of the upper jaw. In vipers it is much shorter.
SupratemporalA long bone on the side of the braincase. The quadrate hangs from its rear end.
PterygoidA long bone of the roof of the mouth. It runs back toward the quadrate and carries teeth of its own.
EctopterygoidA short bone that links the maxilla to the pterygoid. Older books call it the transverse bone.
PrefrontalIt sits between frontal bone and maxilla. The eye socket lies behind it.
PremaxillaA small single bone at the tip of the snout.
How this list was compiled: Every name was checked on 2026-10-01 in at least two sources, for facts only and with nothing copied: (1) G. A. Boulenger, The Snakes of Europe, 1913 (public domain), the chapter on the skeleton, https://archive.org/details/snakesofeurope00boul, with the Wikipedia article Snake skeleton, which repeats its wording and is counted with it; (2) H. Gadow, Amphibia and Reptiles, 1901 (public domain), the chapter on snakes, https://archive.org/details/amphibiareptiles00gado; (3) a university library of CT scans, the page on the skull of a python, http://digimorph.org/specimens/Python_molurus/; (4) Wikipedia, Snake, the section on the skeleton. That the tail vertebrae carry no ribs is in (1) and (4); (2) differs and says all the vertebrae except the atlas carry ribs. A bone only one of them names is not a part of this page. Licence: own work
The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work
How it works
This labeled snake skeleton diagram shows a python, a snake that still has pelvic spurs. First comes the whole skeleton from above: skull, backbone and ribs. Then the skull from the side, with the mouth open.
Read the full guide
The whole skeleton
A snake's skeleton is a skull, a long backbone and ribs. Each vertebra of the body carries a pair of curved ribs; the short tail has none. Where the tail begins, a python has two small claws, the pelvic spurs.
The skull
The braincase is one solid box. The other bones hang loosely from it: the supratemporal reaches back, the quadrate slants down from its end, and the lower jaw meets the quadrate. The dentary is the front, toothed bone of the lower jaw.
To find the quadrate, start at the jaw joint and go up: it is the strut between the lower jaw and the skull.
Questions and answers
Do snakes have bones?
Yes. A snake is a vertebrate. Its skeleton is a skull, a very long backbone and a pair of ribs on almost every vertebra of the body.
How many bones does a snake have?
There is no one number: it changes with the kind of snake. Nearly all of the bones are vertebrae and ribs, and with a pair of ribs on each body vertebra a snake has hundreds of bones.
Do snakes have ribs?
Yes, a pair on each vertebra of the body, from just behind the head to where the tail begins. The ribs are long, curved and movable. The vertebrae of the tail have no ribs.
Do snakes have leg bones?
Most have none. Pythons and boas keep small remains of the hip and hind legs. They end in a claw-like spur on each side of the vent, called a pelvic spur.
How does a snake open its mouth so wide?
The jaw bones are loosely joined to the braincase. The lower jaw hangs from a movable strut, the quadrate, and its two halves are joined at the chin only by a stretchy ligament, so they can spread apart.