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For decades the concept that the mammalian brain is especially suited for complex cognition has been well accepted. In recent years, birds have been shown to match, or even outperform, many mammals on similar tests for cognitive ability. Birds and mammals evolved from reptilian ancestors, raising the question of whether reptilian ancestors may have already had the neural circuitries necessary for complex cognition. To date, the reptilian brain has not been examined in the same detail as that of the mammalian or avian brain. The present proposal includes one aspect of a series of experiments designed to fill this void. Using MR imaging, the aim was to identify neuroanatomical areas for the Nile crocodile (Crocodylus Niloticus) in an attempt to create a 3D atlas of the reptilian brain.
Three crocodiles were euthanized with body masses of around 5 kg. The heads were perfusion fixed with 1% Dotarem. Dotarem (Gadoteric acid) is a contrast agent used in MR imaging, increasing the resolution capacity of the MR scanner. T2-weighted 3D images were acquired for analysis.
Preliminary analysis indicates the identification of 28 anatomical regions within the crocodile brain, showing striking resemblance to the avian brain, accompanied by many differences with other reptiles.

Brendan Billings is Curator of the Raymond Dart Collection of Human skeletons at Wits. He is also a lecturer to undergraduate health sciences and science students at the same university. Until recently he ran the popular Bone Detective tour series at Sterkfontein Caves, having been an active tour guide in the Cradle of Humankind since 2008. He is the recipient of many awards, several staff bursaries from Wits and notably, two from PAST (Palaeontological Scientific Trust).  He is now focussing his energies on his PhD which is in Comparative Neuroanatomy. The title of his thesis is "The Neural basis of Cognition in Crocodiles: Tracing the Roots of Cognition".