Dental batteries

In my recent post on sauropod teeth I noted how the jaws of Nigersaurus looked a little like those of hadrosaur and iguanodontids. Here is a real dental battery, or rather a cast of one. This sits on display in Japan and where people are encouraged to touch and feel it, hence the wear and loss of colour in the middle. Even so, you can see the large numbers of teeth, lying in interlocking banks with each tooth being rather diamond shaped.

This is of course half of a mandible, but a similar pattern is seen in the maxilla such that there are two massed ranks of teeth on each side of the jaws. As the animals bite down these ranks of teeth rub past each other meaning that there are effectively massive grinding surfaces and will do real damage to any plant material in there. It’s a wonderfully effective way of chewing and if you’ve seen isolated teeth from these animals you’ll know just how much damage they can suffer as probably hundreds of times a day they would be abraded against a bank of teeth on the other half of the jaw. That’s guaranteed to do some serious damage to the enamel and even dentine. This is course is where the replacement rate of teeth becomes important as the new teeth coming up into the jaw to replace the old means that the dental battery is generally complete and in good condition. Quite the system really.