August 2012

A Spikey Question.

Do snakes grow a single set of teeth or do they replace teeth throughout their life?

Answer

Headshot of a Taipan (Oxyuranus scutellatus) with their characteristic angular brow Taipan skull currently on display at the Queensland Museum. Taipan skull currently on display at the Queensland Museum.

Snakes constantly grow and replace teeth throughout their lifetime. Replacement teeth arise behind the active teeth, and replace the old teeth when needed. Animals with this type of dentition are termed “polyphdont”.

Snakes have several types of teeth.  The simplest are aglyphous (“without fangs”). In this group the teeth (two rows of teeth on the upper jaw and one row on the lower jaw) are short and hook-like. Those snakes with only aglyphous teeth are non-venomous, local examples include the harmless Common Tree Snake and the Keelback.

Some snakes are opisthoglyphous, or “rear-fanged”. Opisthoglyphous snakes have some of their teeth modified for venom delivery. These modified teeth can be called fangs, and are always situated at the back of the mouth, not the front. The fangs have a grooved surface which allows for venom to be delivered into punctures caused by a bite. This venom delivery system is relatively inefficient and only works properly once the snake’s prey is securely held in the mouth. In Australia, snakes with this “rear-fanged” dentition aren’t dangerous to humans. The most effective venom delivery apparatus is the hollow “hypodermic-style” fang mounted at the front of the mouth. These fangs can be fixed (proteroglyphous) or they can fold back (solenoglyphous). All dangerous Australian snakes have fixed fangs. Like the other teeth, fangs can also be replaced. Once a fang is “worn out”, it falls out (just like our baby teeth), and, within a few days, a new fang moves into position ready for use!

 

 

 

 

 

 

 

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