Erpetosuchus granti (Newton 1894) Late Carnian, Late Triassic, ~60 cm in length. Only the front half of Erpetosuchus is known. Erpetosuchus was derived from a sister to Tarjadia and Parringtonia (below) and with Decuriasuchus. Erpetosuchus represents the last of its lineage, judging by its odd morphology.

Distinct from Parringtonia the skull of Erpetosuchus was most unusual in palatal view where the maxillae and jugals expanded medially to produce wide flat plates that crowded the pterygoid, palatine and ectoptergyoid together in the middle. Teeth erupted only in the anterior jaws. The orbits opened dorsally. The light build of its skeleton along with its phylogenetic nesting suggests that Erpetosuchus was a likely biped.

The skull of Erpetosuchus shares several traits with Tarjadia. These traits are not listed as characters in the LRT.

1. Posterior maxilla undercut with cheek region
2. Maxillary teeth restricted to anterior half of the maxilla
3. Upper temporal fenestrae wider than long
4. Antorbital fossa larger than orbit
5. Mandible not gracile
6. Three processes extend from squamosal in lateral view
7. Posterior skull widest posteriorly

Tarjadia ruthae (Arcucci et al. 1998; Ezcurra et al. 2017; Middle Triassic) According to Wikipedia, "Prior to 2017, most studies placed it outside Archosauria as a member of Doswelliidae. The 2017 specimens show that it belonged to the Erpetosuchidae, a clade that arises between Decuriasuchus and Poposauria+ Archosauria.

Parringtonia gracilis (Huene 1939; Nesbitt and Butler 2012; Middle Triassic) was traditionally considered close to Erpetosuchus, even when just a few bone scraps were known (upper illustration). Recent finds have filled out the rest of the skeleton.

Arcucci A and Marsicano CA 1998. A distinctive new archosaur from the Middle Triassic (Los Chañares Formation) of Argentina. Journal of Vertebrate Paleontology. 18 (1): 228–232.

Benton MJ and Walker AD 2002. Erpetosuchus, a crocodile-like basal archosaur from the Late Triassic of Elgin, Scotland, Zoological Journal of the Linnean Society 136:25-47.

Ezcurra MD et al. (9 co-authors) 2017. Deep faunistic turnovers preceded the rise of dinosaurs in southwestern Pangaea, Nature Ecology & Evolution (2017) doi:10.1038/s41559-017-0305-5

von Huene F 1939. Ein kleiner Pseudosuchier und ein Saurischier aus den ostafrikanischen Mandaschichten. Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, Beilage-Band, Abteilung B. 81 (1): 61–69.

Nesbitt SJ and Butler RJ 2012. Redescription of the archosaur Parringtonia gracilis from the Middle Triassic Manda beds of Tanzania, and the antiquity of Erpetosuchidae. Geological Magazine: 1. doi:10.1017/S0016756812000362

Nesbitt SJ, Stocker MR, Parke WGr, Wood TA, Sidor CA and Angielczy KD 2018. The braincase and endocast of Parringtonia gracilis, a Middle Triassic suchian (Archosaur: Pseudosuchia) Journal of Vertebrate Paleontology 37, Memoir 17: Vertebrate and Climatic Evolution in the Triassic Rift Basins of Tanzania and Zambia.

Newton TE 1894. Reptiles from the Elgin Sandstone—Description of two new genera. Philosophical Transactions of the Royal Society of London, B, 185:573–607.

Olsen PE, Sues, H-D and Norell MA 2000. First record of Erpetosuchus (Reptilia: Archosauria) from the Late Triassic of North America. Journal of Vertebrate Paleontology 20 (4): 633-636. Online pdf

wiki/Tarjadia
wiki/Parringtonia
wiki/Erpetosuchus