Last month I decided not to do a ‘Skull of the Month‘ and I think that I’m going to make this one my last. This is because whilst I have enjoyed learning about animals and their bones I have found it difficult at times to find good material to read and report. Instead I intended to focus on cases studies of human pathology in the archaeological record. If I then come across interesting articles relating to animals and their bones I’ll include that too.
For this final Skull of the Month I have chosen the hippo (Hippopotamus amphibius). These mammals are incredible animals with a huge amount of power and strength. There’s no particular reason why I chose the hippo other than they are one of the most dangerous animals in the world and that I have a picture of a hippo skull which I took on my visit to the Grant Museum last month.
The most adaptive feature of this skull is that the eyes, ears and nostrils are positioned on top of the head. This allows the hippo to almost fully submerge itself underwater to protect itself from the heat and sunburn.
The second most distinguishable feature of the skull is the animals teeth. The hippos canines and incisors are tusk like and are very formidable with the incisors reaching up to 40cm in length and the canines 50cm an sharpen themselves by grinding together. These teeth are used in mouth-to-mouth combat when fighting over breeding territory and access to females. This can be an in true spectacle and are often shown on wildlife documentaries.
In addition to the canines and incisors are the molars which are used for grinding vegetation which they forage at night. The complete dental formula for the hippo is I: 2-3/1-3, C: 1/1, P: 4/4 and M: 3/3. The lower set of set are situated in a flattened, dish shaped jaw that is hinged, which allows the hippo to open it’s mouth to 150 degrees.
This slow moving, semi-aquatic animal has a small brain case and dense bones. It also has the whale as it’s closet living relative. I hope to explore this further by investigating the evolutionary history of the hippo, as well as looking for more information about the structure of its bones. It will be interesting what sort of information has been found about this fearsome but amazing creature and I look forward to finding out.