December 28, 2015
This week’s Monday Geology Picture is an aulacephalodon selfie that I took with the aulacephalodon model that is on display in the Geology Department at Rhodes University in Grahamstown, South Africa. Try saying that three times fast: aulacephalodon selfie, aulocephalodon selfie, aulacephalodon selfie! Can you say it without stumbling? I certainly can’t!
So, what is an aulacephalodon?
Here’s a description from the information sign next to the sculpture:
Aulacephalodon was a relatively large, plant-eating (herbivorous) dicynodont that lived during the Late Permian [~250 million years ago]. Like most other dicynodonts, Aulacephalodon had a beak for biting, grinding, and cutting plants. The animals also had a pair of prominent tusks, possibly for digging, sexual display, and defence [that’s how the South Africans spell “defense”]. The larger, and therefore older, specimens have distinctive bony knobs on the snout above the nasal openings. This feature is not seen in small juvenile skulls. These “nasal bosses” were either only developed in older animals, or they formed to mark either the male or female of the species. Note the prominent “hole” in the top of the skull – a structure known as the pineal foramen, common to all therapsids (mammal-like reptiles). This hole in the skull housed part of a sense organ which was capbale of sensing light and may have regulated the day/night cycle of the animals. Fossil footprints tell us that Aulacephalodon lived in family groups. This model reconstruction is based on the numerous fossil skulls and skeletal remains of Aulacephalodon that have been found in the Cistecephalus Biozone of the Karoo basin. The stance of the model is based on the footprints preserved in the ancient paleosurface (mudflat) that has been exposed in the “Asante Sana” valley, east of Graaf-Reinet.
Here are a few more pictures of Mr. (or Ms.? I’m not sure how to tell…) Aulacephalodon:
The aulacephalodon model is fantastic, both for selfies and as a sort of department mascot. I hope that the geology students sometimes dress up the model for holidays and such! I can just imagine this guy (or lady?) dressed up with a scarf and hat in the wintertime!