What is a python?

Obviously pythons are snakes, and generally big snakes at that, but what makes a python different from all other snakes?

Pythons are widely believed to be a primitive group of snakes and this is best seen by looking at their spurs....these are small remnants of hind limbs that are connected to the spine by pelvic bones. An X-ray of a python will show these tiny, much reduced pelvic and hind limb bones. The presence of these vestigial pelvic / hind limb bones sets the pythons (and boas) apart from all other snakes seen in the hobby (although other, more primitive snakes such as the blindsnakes and pipe snakes also have vestigial pelvic / hind limb bones).

Pythons also have large mouths, this sets them apart from other primitive snakes (blind snakes etc) which have much narrower mouths.

Most pythons (and many boas) have heat-sensory pits in the scales around their mouths, used for detecting ambient temperature as well as their typically warm-blooded prey. Only the pit-vipers share this sense.

Pythons are most likely to be confused with the boas, to which they are very closely related. Several features can be used to distinguish the two groups though:

- pythons lay eggs whereas boas are live-bearers
- pythons have teeth in the jawbone that lies directly below their snout,
whereas boas lack teeth here
- pythons are found in sub-Saharan Africa, Asia and Australia, whereas
boas are found in North America (barely), Central & South America, and oddly a
few reach New Guinea and a few Pacific Islands; the sand boas are restricted to
the Northern Hemisphere and are found in West Asia, North Africa and parts of
the western USA
- most pythons have their heat-sensitive pits WITHIN the labial scales,
whereas most boas have them BETWEEN the labial scales