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

SENNIKOV, ANDREY G; GOWER, DAVID J; EZCURRA, MARTÍN D; BUTLER, RICHARD J

ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018

0024-4082

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 hasexpanded 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 skeletonhas been published. Garjainia prima, from the upper Olenekian of Russia, represents one of the oldest knownerythrosuchids and includes the best-preserved skull of an Early Triassic erythrosuchid. Here, we expand understandingof erythrosuchid anatomy by providing the first detailed and comprehensive description of the holotype ofGarjainia prima. We consider ?Vjushkovia triplicostata? to be a junior synonym of Garjainia prima, because of theirextremely similar morphology, with the two character states that differ between them being variable intraspecificallyin some other diapsids. A new phylogenetic analysis recovered a monophyletic Garjainia as sister to Middle Triassicerythrosuchids and recovered Fugusuchus hejiapanensis as sister to all other erythrosuchids. Branch support forErythrosuchidae 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.