October 2015

Strange Skull

We found this small skull on open grass in a rural residential area. The sharp canine teeth and the 'tusk' through the eye socket seem unusual. Can you tell me what this critter might have been?

Answer

Photo by Helen Manning

You have found the skull of a Bandicoot. The ‘tusk’ that you see through the eye socket is actually part of the lower jaw (mandible) that attaches to the upper jaw (maxilla) with muscle and tendon. As the fleshier parts of the animal decay and disintegrate the jaw sections separate.

Sometimes skulls of different species look very similar. We can use characteristics of the skull structure to identity the specimen. Size of the skull is a good place to start as obviously a rat skull will be quite a bit smaller than a larger mammal such as a wallaby or a koala. Providing, a scale in images sent to the museum for identification is extremely helpful. Your use of a ruler in the image is great.

Position of the eye sockets can indicate species type such as predator or prey. Eye sockets on the side of the head tend to indicate prey animals while eye sockets facing the front suggest predatory animals
Specific animals have particular dentition (numbers and types of teeth). There are four major types of teeth in mammals: incisors, canines, premolars, molars

Carnivores have all four types, while some herbivores have just incisors and or premolars and molars.
The skull you have found has a long snout and distinctive canines these characteristics tell us you have found a bandicoot. There are a number of species of Bandicoot but we can use the location of your specimen to narrow it down to 2 species that are distributed there.

Of these two species the size of the ear bones as well as the arrangement of the incisors and the size of the 4th molar determines which of these two species you have found. The limited detail visible in your photograph indicates that your bandicoot was probably a Northern Brown (Isoodon macrourus).

Queensland Museum's Find out about... is proudly supported by the Thyne Reid Foundation and the Tim Fairfax Family Foundation.