Mandasuchus is an extinct genus of loricatan pseudosuchian from the Manda Formation of Tanzania, which dates back to the Anisian stage of the Middle Triassic. Although this genus was first mentioned by Alan Charig in 1956,[1] a formal description was not published until 2018.[2]
The name was first used in a 1956 doctoral dissertation by Alan J. Charig of the University of Cambridge, along with Teleocrater, an archosaur formally named in 2017.[3] Several well preserved specimens have been found, although there is little cranial material.
The family Prestosuchidae was erected in 1967 by Alfred Romer to include Mandasuchus and three other formally named genera of "rauisuchians".[4][5] Charig and two coauthors suggested in a 1965 study dealing with saurischians that Mandasuchus was a possible ancestor of the "prosauropods" (basal sauropodomorphs), without explanation.[6][7] In his 1993 study of the phylogeny of Crocodylotarsi (croc-line archosaurs, now known as Pseudosuchia), J. Michael Parrish argued that Mandasuchus was not a distinct genus. He proposed that it was in the same genus as the European archosaur Ticinosuchus ferox due to the similarity of some homologous postcranial bones, but withheld final taxonomic determination of Mandasuchus until Charig provided a published description of the material.[8] However, Charig died in 1997 without publishing on many of the archosaurs he discovered. Mandasuchus was finally formally described in 2018 by Richard J. Butler and colleagues, as part of a multinational investigation into the fossils of Triassic rift systems in Tanzania and Zambia. A phylogenetic analysis recovered it as a loricatan more basal than Prestosuchus and not synonymous with Ticinosuchus, albeit not too distantly related either.[2]
Skull material for Mandasuchus is limited to maxillae and part of a dentary. The maxilla is low, with an elongated antorbital fenestra and at least 12 tooth sockets separated by discrete interdental plates. The antorbital fenestra is surrounded by an inset basin, the antorbital fossa, as with other archosaurs. However, Mandasuchus has a restricted and weakly differentiated antorbital fossa compared to other loricatans and Ticinosuchus. The ascending (or dorsal) process of the maxilla, which lies in front of the antorbital fenestra, is short and very thin. This process is also uniquely diagonally oriented when seen from above, with its rear edge set inwards from the front edge. The only preserved tooth is thin and serrated. The dentary fragment is incomplete, but seemingly slender and similar to the maxilla.[2]