Bukobay Svita

Bukobay Svita
Stratigraphic range: Ladinian ~
"Mastodonsaurus" torvus, an index fossil of the Bukobay Svita / Gorizont
Type	Stratigraphic Formation
Overlies	Donguz Svita
Lithology
Primary	Claystone, siltstone
Other	Sandstone
Location
Coordinates	51°24′N 55°30′E / 51.4°N 55.5°E / 51.4; 55.5
Approximate paleocoordinates	35°24′N 41°00′E / 35.4°N 41.0°E / 35.4; 41.0
Region	Orenburg, Bashkortostan
Country	Russia
Bukobay Svita (Russia)

The Bukobay Svita (also anglicized as Bukobay or Bukobai Formation) is a Middle Triassic geological unit in Russia.¹²³ It is composed primarily of red or grey lacustrine sediments, reconstructing a humid and marshy depositional environment. Bukobay is the youngest section of a Triassic terrestrial succession exposed south of the Ural Mountains. It is equivalent to a biostratigraphic unit, the Bukobay Gorizont, which is also called the "Bukobay Horizon" or "Mastodonsaurus" fauna).

Notable components of the Bukobay fauna include Mastodonsaurus torvus (a giant capitosaur amphibian), Malutinisuchus gratus, Plagiosternum danilovi, Synesuchus muravjevi, Jushatyria vjushkovi⁴ and Energosuchus garjainovi, the insects Mesoneta uralensis and Triassomachilis uralensis, Elatosaurus facetus, dicynodonts Planitorostris pechoriensis, Elephantosaurus jachimovitschi (a large dicynodont), and Chalishevia cothurnata (the youngest known erythrosuchid). Temnospondyls include Bukobaja enigmatica, Plagioscutum caspiense and Plagiorophus paraboliceps, with Ceratodus orenburgensis, C. jecticristatus and C. bucobaensis as fish. The flora is also diverse, including Equisetites arenaceus (a species of giant horsetails), ferns Cladophlebis shensiensis, Danaeopsis rarinervisand, Lepidopteris microcellularis, ginkgophytes Sphenobaiera granulifer, Glossophyllum sp., cycadophytes Apoldia surakaica and Ladinian-age palynomorphs.⁵⁶ Also found in the formation were unidentified species from the genus Mastodonsaurus sp., Cyclotosaurus sp., Pistosaurus sp., Bukobaja sp. and Chalishevia sp., as well as remains from the order Theriodontia indet., Kannemeyeroidea indet. and Mastodonsauridae indet..