Several skulls and skeletons have been attributed to Proterosuchus, the basalmost archosauriform. Unfortunately the holotype is the worst of the lot.
Figure 1. Top and bottom images of Proterosuchus holotype from Ezcurra and Butler 2014. Middle with missing pieces imagined and restored based on other specimens. As you can see, the bones and impressions of bones are very difficult to see. Colorizing the bones, as I do in DGS, is an amazing way to present what those two observed in the fossil.
A recent paper by Ezcurra and Butler 2014 explores the many skulls of Proterosuchus.
From the abstract
“Based upon a comprehensive re-examination of all known specimens, as well as examination of other proterosuchid taxa in collections worldwide, we conclude that the holotype of Proterosuchus fergusi (Fig. 1) is undiagnostic… As a result, we recognize a minimum of four archosauriform species following the Permo-Triassic mass extinction in South Africa. Our results suggest a greater species richness of earliest Triassic archosauriforms than previously appreciated, but that archosauriform morphological disparity remained low and did not expand until the late Early Triassic – early Mid-Triassic.”
This skull, IMHO, cannot be used in phylogenetic analysis, and it hasn’t been used in that way. However, add a few other taxa identified by museum numbers and you’re good to go.
References
Broom R. 1903. On a new reptile (Proterosuchus fergusi) from the Karroo beds of Tarkastad, South Africa. Annals of the South African Museum 4: 159–164.
Ezcurra, MD and Butler RJ. 2014. Taxonomy of the proterosuchid archosauriforms (Diapsida: Archosauromorpha) from the earliest Triassic of South Africa, and implications for the early archosauriform radiation. Palaeontology. (advance online publication)
DOI: 10.1111/pala.12130 http://onlinelibrary.wiley.com/doi/10.1111/pala.12130/abstract
Ezcurra MD, Butler RJ and Gower D 2013. ‘Proterosuchia’: the orign and early history of Archosauriformes. Pp. 9–33 in S. J. Nesbitt, J. B. Desojo, R. B. Irmis (eds) Anatomy, Phylogeny and Palaeobiology of Early Archosaurs and Their Kin. Geological Society, London, Special Publications 379.
Welman J 1998. The taxonomy of South African proterosuchids (Reptilia, Archosauromorpha). Journal of Vertebrate Paleontology 18:340–347.
Welman J and Flemming AF 1993. Statistical analysis of the skulls of Triassic proterosuchids (Reptilia, Archosauromorpha) from South Africa. Palaeontologia africana 30:113–123.
The Pterosaur Heresies 
TM201 was discovered at Harrismith Primary school in a gully known from older maps as the K*kspruit.( I kid you not) owing to the fact that it ran through or close to the stables in the Algo-Boer War. I’m looking for photographs of the animal. The whole school sat in the coldest conditions watching Dr. Frans du Randy take it out. I lost contact with the fossil and have only recently managed to find it. I have a copy of a Proterosuchus because I ran dinocamps and Walking with Harrismith Monsters day for many years. I’m retiring at the end of the year and look forward to getting involved at the dinosaur centre in some way. Miss L.A. Luff
Thank you for touching base with that intimate insight.
I’ve just left a comment on the fact I made a mistake with TM201. That fossil was named in the early 1900. “My fossil” was found in about July 1993. I have found the notes and the story of that day. I’m looking to find the newspaper article about that day as further confirmation. It seems that my fossil did not receive a number. I’m trying to find it, as I would like to add the information into our Facebook page at school. I also want it recorded that the person who found the animal was myself. Mrs Sonia MacDonald contacted Dr. Francois du Randt.