Upper Permian vertebrates and their sedimentological context in the South Urals, Russia

Saurichthys and other fossil fishes from the late Smithian (Early Triassic) of Bear Lake County (Idaho, USA), with a discussion of saurichthyid palaeogeography and evolution

“…Isolated teeth with the aforementioned features that are found in Late Permian (e.g. Tverdokhlebov et al 2005) and Triassic strata are often ascribed to Saurichthys, but their taxonomic affiliation is mostly controversial (e.g. Gardiner 1960, Griffith 1962, Stensiö 1919, Storrs 1994.…”

The origin and significance of pedogenic dolomite from the Upper Permian of the South Urals of Russia

“…This abrupt change in sedimentary facies across the P-Tr boundary is thought to be related to reductions in vegetation cover in the drainage basin caused by the mass extinction event (Newell, Tverdokhlebov & Benton, 1999). Distal from the Ural Mountain Belt, which formed the primary source of sediment, fluvial deposits are interbedded with aeolian sandstones (for extended palaeogeographic discussion see Newell, Tverdokhlebov & Benton, 1999;Tverdokhlebov et al 2002Tverdokhlebov et al , 2005. During Late Permian and Early Triassic time, the studied sections were at an estimated palaeolatitude of [30][31][32][33][34][35] • N (Van der Voo & Torsvik, 2004;Taylor et al 2009).…”

The westernmost occurrence of <i>Gnathorhiza</i> in the Triassic, with a discussion of the stratigraphic and palaeogeographic distribution of the genus

“…Only ratios of one lower tooth plate is taken into account, because the first ridge rest of tooth plates is broken in our material. The Russian regional stratigraphy (see Tverdokhlebov et al, 2005, for details) is used here for Russian localities and the Czatkowice 1 site. Minikh, 1977): Mediumsized tooth plates with an obtuse inner angle (lower about 125 • , upper about 140 • ); radiating ridges straight, narrow and acute, originate from one point at the mediolingual junction; four ridges in upper tooth plates, three in lower ones; lingual edge slightly concave; big, cone-shaped cusps present on ridges crests; in upper tooth plates the first ridge about 2 times longer than the second and fourth ridges; in lower tooth plates the first ridge about 2 times longer than the second one, and about 1.5 times longer than the third one; pterygopalatine ascending process originates above the second ridge of the upper tooth plates, and is short and slightly curved posteriad; prearticular sulcus single and shallow; prearticular symphysis half-oval; furrows between ridges are throughout; interridge furrows very deep; occlusal pits absent; enamel to bone junction straight; tooth plates do not contact in the midline.…”

“…2a). These sediments were formed in lakes and on flood plains in a rather dry climate (Tverdokhlebov et al, 2005). Minikh (1992) mentioned also burrows found in sediments of the same age, but none of them contained fossils.…”

“…Gnathorhiza: Germany, Saar-Nahe Basin (Boy and Schindler, 2000;Schindler, 2007); 11, G. tatarica, G. otschevi: Russia, Orenburg region, Kutulukskaya Svita (Minikh, 1989(Minikh, , 1992, Gnathorhiza sp. : Kulchumovskaya Svita (Tverdokhlebov et al, 2005); 12, Gnathorhiza sp. : Brazil, Sao Paulo State, Corumbatai Formation, Paraná State, Rio do Rasto Formation (Toledo and Bertini, 2005); 13 Gnathorhiza sp.…”