Last Friday I gave you a really difficult mystery object to identify, in the form of this mysterious caramel-brown lump:
It turns out that for the first time in ages, nobody managed to get the right identification, although there were a lot of great suggestions ranging from “headless, legless rubber chicken. Which has been burned in a fire some great time ago” by Matt H., to a hyperostotic fish spine, which Jake and henstridgesj had in mind.
This lump is in fact a dentine nodule from inside the tusk of an African Elephant Loxodonta africana (Blumenbach, 1797).
These sorts of internal growths form when a tusk gets damaged and the pulp inside becomes infected. New dentine is laid down in response to the infection, walling off the affected tissue and preventing the further spread of bacteria.
These growths come in a variety of forms – none of which look much like ivory. Here’s a selection to give you an idea:
So the next time you find something that looks like a burnt rubber chicken, or an overly firm bit of ginger, you may want to check to make sure it’s not ivory.