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GENUS RAUISUCHUS VON HUENE, 1938 A Type and only known species Rauisuchus tiradentes von Huene, 1938a. Diagnosis As for the type species (by monotypy)., Published as part of Lautenschlager, Stephan & Rauhut, Oliver W. M., 2015, Osteology of Rauisuchus tiradentes from the Late Triassic (Carnian) Santa Maria Formation of Brazil, and its implications for rauisuchid anatomy and phylogeny, pp. 55-91 in Zoological Journal of the Linnean Society 173 (1) on page 58, DOI: 10.1111/zoj.12196, http://zenodo.org/record/5330952, {"references":["von Huene F. 1938 a. Die fossilen Reptilien des sudamerikanischen Gondwanalandes. Ergebnisse der Sauriergrabung in Sudbrasilien 1928 / 29. Neues Jahrbuch fur Mineralogie, Geologie und Palaontologie, Referate 1938: 142 - 151."]}

RAUISUCHUS TIRADENTES Rauisuchoid ilium The only known ilium (BSPG AS XXV 88; Fig. 17A, B) originally assigned to R. tiradentes is a left element and comes from the secondary fossil site as part of ‘ Find 1025’. Compared with the pubis of the lectotype it shows a notable difference in size and is from an individual that was at least 20–25% smaller than the lectotype. The ilium consists of an acetabular area and the iliac blade with two processes: an anterior preacetabular process and a posterior postacetabular process. The lateral surface of the main body is nearly entirely occupied by a deep acetabulum. A prominent supraacetabular rim surrounds the dorsal margin. Anteriorly, the main body possesses a spike-like, dorsally flattened projection, which forms the pubic process. In this region the supra-acetabular rim is strongly developed. Anteroventrally, below the pubic process, the ilium bears a longitudinal groove with a depression on the ventralmost part, forming the articulation socket for the pubis. The parallel acetabular rim is not interrupted, indicating that the pubis only marginally contributed, or did not contribute at all, to the acetabulum. The posteroventral part of the ilium is partly broken. The area where the ischiadic process would be located is missing. The preacetabular process is short and projects anteriorly, but does not extend anterior to the pubic process. It has a blunt outline and is only slightly separated from the main body. The postacetabular process is considerably elongated and projects posteriorly and slightly laterally, although the latter might be a preservational artefact. Its cross section is triangular with a rounded lateral side. The medial(?) side is covered by a ventromedially excavated depression. Posteriorly it tapers to a blunt tip. Above the supra-acetabular rim, located between the preacetabular and the postacetabular process, the ilium possesses a prominent supra-acetabular ridge or buttress. It is perpendicular to the longitudinal axis of the iliac blade and contacts the dorsal margin to the supra-acetabular rim. According to Colbert (1961) and Chatterjee (1985), this ridge represents the attachment point for the iliofemoralis or the iliotibialis muscle, although this inference has been debated (Gower, 2000). On the medial side of the ilium, four distinct depressions are visible, which most probably represent the articulation sockets for the two-pronged sacral ribs of the sacral vertebrae. As no corresponding or overlapping elements are preserved in the lectotype, the ilium cannot be referred to R. tiradentes, although the following characteristics support its classification as a rauisuchoid ilium: (1) the ilium contributes to the major part of the acetabulum; (2) presence of a supraacetabular rim; (3) a short preacetabular and an elongated postacetabular process; (4) presence of a supraacetabular ridge connecting the supra-acetabular rim and the dorsal margin of the ilium; (5) closed acetabulum (Gower, 2000; Nesbitt, 2011). The fact that the acetabulum is almost entirely or even entirely placed on the ilium might indicate that it was correctly assigned to R. tiradentes, as the latter lacks an acetabular facet on the pubis; however, this can only be confirmed by additional material., Published as part of Lautenschlager, Stephan & Rauhut, Oliver W. M., 2015, Osteology of Rauisuchus tiradentes from the Late Triassic (Carnian) Santa Maria Formation of Brazil, and its implications for rauisuchid anatomy and phylogeny, pp. 55-91 in Zoological Journal of the Linnean Society 173 (1) on pages 82-83, DOI: 10.1111/zoj.12196, http://zenodo.org/record/5330952, {"references":["Colbert EH. 1961. The Triassic reptile Poposaurus. Fieldiana Geology 14: 59 - 78.","Chatterjee S. 1985. Postosuchus, a new thecodontian reptile from the Triassic of Texas and the origin of tyrannosaurs. Philosophical Transactions of the Royal Society, London 309: 395 - 460.","Gower DJ. 2000. Rauisuchian archosaurs (Reptilia, Diapsida): an overview. Neues Jahrbuch fur Geologie und Palaontologie, Abhandlungen 218: 447 - 488.","Nesbitt SJ. 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 1 - 292."]}

Postosuchus kirkpatricki Chatterjee, 1985 (fig. 11C) AGE: Norian, Late Triassic (Lehman and Chatterjee, 2005). OCCURRENCE: Post (5 Miller) Quarry, Cooper Canyon Formation, Dockum Group (Chatterjee, 1985). HOLOTYPE: TTU-P 9000, skull and partial skeleton. PARATYPE: TTU-P 9002, skull and skeleton. REMARKS: See Nesbitt et al., 2009a. KEY REFERENCES: Chatterjee, 1985; Long and Murry, 1995; Weinbaum, 2002; Peyer et al., 2008., Published as part of Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, pp. 1-292 in Bulletin of the American Museum of Natural History 2011 (352) on page 37, DOI: 10.1206/352.1, http://zenodo.org/record/5405335, {"references":["Chatterjee, S. 1985. Postosuchus, a new thecodontian reptile from the Triassic of Texas and the origin of tyrannosaurs. Philosophical Transactions of the Royal Society of London B 309: 395 - 460.","Lehman, T., and S. Chatterjee. 2005. Depositional setting and vertebrate biostratigraphy of the Triassic Dockum Group of Texas. Journal of Earth Systems and Science 114: 325 - 351.","Nesbitt, S. J., M. R. Stocker, B. Small, and A. Downs. 2009 a. The osteology and relationships of Vancleavea campi (Reptilia: Archosauriformes). Zoological Journal of the Linnean Society 157: 814 - 864.","Long, R. A., and P. A. Murry. 1995. Late Triassic (Carnian and Norian) tetrapods from the southwestern United States. New Mexico Museum of Natural History and Science Bulletin 4: 1 - 254.","Weinbaum, J. C. 2002. Osteology and relationships of Postosuchus kirkpatricki (Archosauria: Crurotarsi). Lubbuck: Texas Tech University, 78 pp.","Peyer, K., J. G. Carter, H. - D. Sues, S. E. Novak, and P. E. Olsen. 2008. A new suchian archosaur from the Upper Triassic of North Carolina. Journal of Vertebrate Paleontology 28: 363 - 381."]}

Archosaurs have a nearly 250 million year record that originated shortly after the Permian-Triassic extinction event and is continued today by two extant clades, the crocodylians and the avians. The two extant lineages exemplify two bauplan extremes among a diverse and complex evolutionary history, but little is known about the common ancestor of these lineages. Renewed interest in early archosaurs has led to nearly a doubling of the known taxa in the last 20 years. This study presents a thorough phylogenetic analysis of 80 species-level taxa ranging from the latest Permian to the early part of the Jurassic using a dataset of 412 characters. Each terminal taxon is explicitly described and all specimens used in the analysis are clearly stated. Additionally, each character is discussed in detail and nearly all of the character states are illustrated in either a drawing or highlighted on a specimen photograph. A combination of novel characters and comprehensive character sampling has bridged previou...

The osteology of an almost complete braincase of the rauisuchian archosaur Batrachotomus kupferzellensis Gower from the Middle Triassic of Germany is described. There is a possibly discrete epiotic ossification, the metotic fissure is undivided by bone (i.e. there is a metotic foramen), the medial wall of the otic capsule is mostly ossified, the cerebral branch of the internal carotid artery entered the lateral surface of the parabasisphenoid, the ventral ramus of the opisthotic is more prominent laterally than a strong subvertical ridge on the exoccipital and basioccipital that lies posterior to the external foramen for the hypoglossal nerve, and the perilymphatic foramen faces away from the otic capsule in a posterior direction. Braincase morphology in the rauisuchians Saurosuchus galilei, Postosuchus kirkpatricki, and Tikisuchus romeri is reviewed. A matrix of 27 braincase characters for 12 archosaurian taxa is analysed. The most parsimonious hypothesis is consistent with the currently orthodox view of archosaurian phylogeny, except in that aetosaurians are more closely related to crocodylomorphs than is any rauisuchian. This phylogeny is used in a brief interpretation of the evolution of derived braincase features present in extant crocodilians. © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society, 2002, 136, 49–76.

TIKISUCHUS ROMERI Tikisuchus romeri Chatterjee & Majumdar is a rauisuchian from the Upper Triassic Tiki Formation of India, known from a single incomplete specimen, ISI R 305. The osteology of this taxon has been described only briefly by Chatterjee & Majumdar (1987). These authors figured a restoration of the braincase in posterior view and presented the following description: ‘braincase very deep with elongated and well pronounced basipterygoid processes; supraoccipital tapers dorsally and makes a movable contact with parietal’ (Chatterjee & Majumdar, 1987: 788). Furthermore, they (p. 787) included ‘ossified laterosphenoid’ in a list of archosaurian features possessed by the specimen. I have re-examined this material as part of this study. The surface preservation of ISI R 305 is very crumbly, and sutures and other details are hard to make out. In addition, several regions of the braincase are not preserved or could not be located at the time of this study. This makes it impossible to comment on the laterosphenoids (which could not be located), exoccipitals, metotic region, fenestra ovalis. The paroccipital processes are fairly short with strong distal expansions. The basioccipital bears dorsal facets that indicate that the ventral ends of the exoccipitals met along the midline to form the ventral border of the foramen magnum. The basal tubera of the basioccipital are barely bilobed. There is no sign that the entrance foramina for the cerebral branches of the internal carotid arteries were located on the posterior or posteroventral wall of the parabasisphenoid. The anterolateral surfaces of the same element are even less perfectly preserved, but I tentatively interpret that this is where the foramina for the cerebral branch of the internal carotid artery are positioned. The braincase of T. romeri resembles that of P. kirkpatricki, particularly in the elongated region of the parabasisphenoid between the basipterygoid processes and the basal tubera, and in the way this region harbours a dorsoventrally elongate median pharyngeal recess. This is a derived feature within Suchia, and it represents a potential synapomorphy shared by P. kirkpatricki and T. romeri to the exclusion of other known suchians, including B. kupferzellensis (although the braincase UMMP 7473 appears to possess a similar feature, see above). One clear difference between the parabasisphenoids of P. kirkpatricki and T. romeri lies in the presence of paired short hook-like (in the transverse plane) processes on the parabasisphenoid of the latter taxon. These are not apparent in Chatterjee & Majumdar’s (1987) figure 2, but they can be clearly detected on the posterior surface of the element between the bases of the basipterygoid processes. In summary, rauisuchian braincases are slowly becoming better known. The braincases of B. kupferzellensis, S. galilei, P. kirkpatricki and T. romeri share many features. Most of these are apparently plesiomorphic for Archosauria (e.g. undivided metotic foramen, external foramina for hypoglossal nerve not posterior to subvertical ridge), some are probably derived for Archosauria (e.g. well ossified otic bullae, lateral foramen for the cerebral branch of the internal carotid artery), but few if any seem to be both derived for Suchia and restricted to rauisuchians. The elongate median pharyngeal recess of P. kirkpatricki and T. romeri is perhaps the only such character. B. kupferzellensis and P. kirkpatricki share a separate foramen possibly for the posterior cerebral/cephalic vein above the dorsal end of the metotic foramen, but a probable equivalent is also present in at least some crocodilians, and the condition in S. galilei and T. romeri is unknown., Published as part of Gower, David J., 2002, Braincase evolution in suchian archosaurs (Reptilia: Diapsida): evidence from the rauisuchian Batrachotomus kupferzellensis, pp. 49-76 in Zoological Journal of the Linnean Society 136 (1) on pages 66-67, DOI: 10.1046/j.1096-3642.2002.00025.x, http://zenodo.org/record/5436041, {"references":["Chatterjee S, Majumdar PK. 1987. Tikisuchus romeri a new rauisuchid reptile from the late Triassic of India. Journal of Paleontology 61: 787 - 793."]}