Data from: The monophyly of Euparkeriidae (Reptilia: Archosauriformes) and the origins of Archosauria: a revision of Dorosuchus neoetus from the Mid-Triassic of Russia

Euparkeria capensis is resolved as the sister taxon to crown Archosauria in many cladistic phylogenies and provides a key outgroup which may approximate the ancestral archosaur morphology. Several other taxa have been referred to the family Euparkeriidae, but the monophyly of this taxon remains doubtful and largely untested. In order to test this monophyly, the archosauriform and putative euparkeriid Dorosuchus neoetus from the Mid-Triassic of Russia is reexamined in light of recent work on the evolution of stem archosaurs. Dorosuchus neoetus is found to possess a number of morphological features that place it close to Archosauria, including a sigmoidal femur with a clear attachment region for the m. caudifemoralis musculature, but no unambiguous archosaurian apomorphies. Dorosuchus neoetus is included for the first time in a numerical cladistic analysis, and is recovered as the sole sister taxon to Archosauria+Phytosauria. A monophyletic Euparkeriidae including D. neoetus and E. capensis is slightly less parsimonious. In addition, a mandible and pterygoid that were previously referred to D. neoetus subsequent to the original description of the species are also included separately within the phylogenetic analysis, and are recovered within crown Archosauria, possibly raising questions as to their correct taxonomic referral. However, this phylogenetic placement is based primarily on the absence of palatal teeth, but the presence or absence of palatal teeth exhibits considerable homoplasy within Archosauriformes. Based on other aspects of their morphology, we do not reject the referral of these elements to D. neoetus

The osteology of the holotype of the early erythrosuchid Garjainia prima (Diapsida: Archosauromorpha) from the upper Lower Triassic of European Russia

Erythrosuchids are Early–Middle Triassic bulky, quadrupedal archosauromorphs with proportionally large heads, and they were among the first archosauromorphs to occupy the role of terrestrial hypercarnivores. Recent work has expanded anatomical and phylogenetic knowledge of erythrosuchids, but a thorough understanding is still lacking, and Erythrosuchus africanus is the only species for which a thorough anatomical description of most of the skeleton has been published. Garjainia prima, from the upper Olenekian of Russia, represents one of the oldest known erythrosuchids and includes the best-preserved skull of an Early Triassic erythrosuchid. Here, we expand understanding of erythrosuchid anatomy by providing the first detailed and comprehensive description of the holotype of Garjainia prima. We consider ‘Vjushkovia triplicostata’ to be a junior synonym of Garjainia prima, because of their extremely similar morphology, with the two character states that differ between them being variable intraspecifically in some other diapsids. A new phylogenetic analysis recovered a monophyletic Garjainia as sister to Middle Triassic erythrosuchids and recovered Fugusuchus hejiapanensis as sister to all other erythrosuchids. Branch support for Erythrosuchidae is low, but the Middle Triassic erythrosuchid clade is well supported by characters with low homoplasy, indicating that their morphology was specialized in ways rarely explored by other Triassic archosauromorphs.Fil: Ezcurra, Martin Daniel. University of Birmingham; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Gower, David J. Natural History Museum; Reino UnidoFil: Sennikov, Andrey G. Kazan Federal University; Rusia. Borissiak Paleontological Institute; RusiaFil: Butler, Richard J. University of Birmingham; Reino Unid

Appendix S4

Adjusted matrix including Dorosuchus neoetus in nexus format

Appendix S3

Unadjusted matrix including Dorosuchus neoetus in nexus format

Appendix S2

Appendix of strict consensus trees from all analyses carried out

Appendix S1

Appendix of measurements of specimens of Dorosuchus neoetus

A New Species of <i>Garjainia</i> Ochev, 1958 (Diapsida: Archosauriformes: Erythrosuchidae) from the Early Triassic of South Africa

<div><p>A new species of the erythrosuchid archosauriform reptile <i>Garjainia</i> Ochev, 1958 is described on the basis of disarticulated but abundant and well-preserved cranial and postcranial material from the late Early Triassic (late Olenekian) Subzone A of the <i>Cynognathus</i> Assemblage Zone of the Burgersdorp Formation (Beaufort Group) of the Karoo Basin of South Africa. The new species, <i>G. madiba</i>, differs from its unique congener, <i>G. prima</i> from the late Olenekian of European Russia, most notably in having large bony bosses on the lateral surfaces of the jugals and postorbitals. The new species also has more teeth and a proportionately longer postacetabular process of the ilium than <i>G. prima</i>. Analysis of <i>G. madiba</i> bone histology reveals thick compact cortices comprised of highly vascularized, rapidly forming fibro-lamellar bone tissue, similar to <i>Erythrosuchus africanus</i> from Subzone B of the <i>Cynognathus</i> Assemblage Zone. The most notable differences between the two taxa are the predominance of a radiating vascular network and presence of annuli in the limb bones of <i>G. madiba</i>. These features indicate rapid growth rates, consistent with data for many other Triassic archosauriforms, but also a high degree of developmental plasticity as growth remained flexible. The diagnoses of <i>Garjainia</i> and of Erythrosuchidae are addressed and revised. <i>Garjainia madiba</i> is the geologically oldest erythrosuchid known from the Southern Hemisphere, and demonstrates that erythrosuchids achieved a cosmopolitan biogeographical distribution by the end of the Early Triassic, within five million years of the end-Permian mass extinction event. It provides new insights into the diversity of the Subzone A vertebrate assemblage, which partially fills a major gap between classic ‘faunal’ assemblages from the older <i>Lystrosaurus</i> Assemblage Zone (earliest Triassic) and the younger Subzone B of the <i>Cynognathus</i> Assemblage Zone (early Middle Triassic).</p></div

Humerus of <i>Garjainia madiba</i> sp. nov.

<p>A–D, BP/1/7336, right humerus in dorsal (A), proximal (B), ventral (C) and distal (D) views. E–G, cast of distal end of right humerus of NMQR 3051 in dorsal (E), distal (F) and ventral (G) views. Abbreviations: dpc, deltopectoral crest; ect, ectepicondylar groove; supr, supinator ridge.</p