Jaikosuchus is an extinct genus of proterosuchid archosauriform. It contains a single species, J. magnus. Fossils have been found from European Russia that date back to the upper Olenekian stage of the Early Triassic.Shishkin, M. A., Ochev, V. G., Lozovskii, V. R. and Novikov, I. V. (2000). Tetrapod biostratigraphy of the Triassic of Eastern Europe. In: M. J. Benton, E. N. Kurochkin, M. A. Shishkin, D. M. Unwin (eds.), The Age of Dinosaurs in Russia and Mongolia. Cambridge University Press, Cambridge. pp. 140–159.
Discovery The genus was originally assigned as a new species of the proterosuchid Chasmatosuchus in 1979, but was later put in its own genus in 1990. It has often been described as an erythrosuchid, a rauisuchian or a basal suchian closely related to rauisuchians rather than the more traditional view of it being a more primitive archosaur.https://www.helsinki.fi/~mhaaramo/metazoa/deuterostoma/chordata/archosauria/pseudosuchia/suchia_2.htmlBorsuk-Bialynicka, M., Cook, E., Evans, S. E. and Maryafiska, T. (1999). A microvertebrate assemblage from the Early Triassic of Poland. Acta Palaeontologica Polonica 44(2):167-188. In 2016, it was synonymized again with Chasmatosuchus by Ezcurra et al., but was revived as a distinct genus by Ezcurra et al. again in a 2023 overview of proterosuchid taxonomy, who found its vertebral morphology to be distinct from that of Chasmatosuchus. Both were placed in the new subfamily Chasmatosuchinae.
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