The Donguz Formation, Donguz Svita, or Donguz Rocks () is a

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is di ...

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

that crops out on the right bank of Donguz River in

Orenburg Oblast Orenburg Oblast (also Orenburzhye) is a federal subject of Russia (an oblast), mainly located in Eastern Europe. Its administrative center is the city of Orenburg. From 1938 to 1957, it bore the name Chkalov Oblast in honor of Valery Chkal ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, across the settlement of Pervomaisky. The formation is equivalent to a

biostratigraphic Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...

unit, the Donguz

Gorizont Gorizont (, ), GRAU index 11F662, was a series of 35 Russian, previously Soviet, geosynchronous communications satellites launched between 1978 and 2000. The program was started in order to develop a satellite system to relay coverage of the 1 ...

. It is famous for its rich collection of the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

s of Middle Triassic

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

s. It is a nature monument (особо охраняемых природных территорий (ООПТ)).Uraloved.ru
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Fossil content

The following fossils have been found in the Donguz Formation: *

Temnospondyls Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order of small to giant tetrapods—often considered primitive amphibians—that flourished wo ...

** '' Eryosuchus antiquus'', Ochev ** '' E. garjainovi'', Ochev ** '' E. tverdochlebovi'', Ochev ** '' Bukobaja''? sp. ** '' Plagiorophus danilovi'' ** '' Plagioscutum ochevi'', Shishkin ** '' Plagiosternum paraboliceps'' (Konzhukova) *

Thecodont Thecodontia (meaning 'socket-teeth'), now considered an obsolete taxonomic grouping, was formerly used to describe a diverse "order" of early archosaurian reptiles that first appeared in the latest Permian period and flourished until the end of t ...

s ** '' Jushatyria vjushkovi'' *

Procolophonid Procolophonidae is an extinct family of small, lizard-like parareptiles known from the Late Permian to Late Triassic that were distributed across Pangaea, having been reported from Europe, North America, China, South Africa, South America, Antarc ...

** '' Kapes serotinus'', Novikov *

Proterosuchid Proterosuchidae is an early family of basal archosauriforms whose fossils are known from the Late Permian and the Early Triassic. The highest diversity of genera is known from European Russia, but fossils are also known from South Africa, India, ...

s ** '' Sarmatosuchus ochevi'', Sennikov *

Erythrosuchid Erythrosuchidae (meaning "red crocodiles" in Greek) are a family of large basal archosauriform carnivores that lived from the later Early Triassic (Olenekian) to the early Middle Triassic (Anisian). Naming The family Erythrosuchidae was named by ...

s ** '' Uralosaurus magnus'', (Ochev) *

Rauisuchidae Rauisuchidae is a group of large (up to ) predatory Triassic archosaurs. Some disagreement exists over which genera should be included in the Rauisuchidae and which should be in the related Prestosuchidae and Poposauridae, and indeed whether the ...

** '' Dongusia colorata'', Huene ** '' Vjushkovisaurus berdjanensis'', Ochev *

Euparkeriidae Euparkeriidae is an extinct family of small carnivorous archosauriforms which lived from the Early Triassic to the Middle Triassic (Anisian). While most other early archosauriforms walked on four limbs, euparkeriids were probably facultative bi ...

** '' Dorosuchus neoetus'', Sennikov *

Dicynodonts Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivores that typically bore a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, t ...

** ''

Kannemeyeria ''Kannemeyeria'' is a genus of dicynodont that lived during the Anisian age of Middle Triassic period in what is now Africa and South America. The generic name is given in honor of Daniel Rossouw Kannemeyer, the South African fossil collector w ...

'' spp. * '' Shansiodon'' ('' Rhinodicynodon'') gracile (Kalandadze) *

Therocephalian Therocephalia is an extinct clade of therapsids (mammals and their close extinct relatives) from the Permian and Triassic periods. The therocephalians ("beast-heads") are named after their large skulls, which, along with the structure of their te ...

s ** '' Dongusaurus schepetovi'', Vyushkov ** '' Nothogomphodon danilovi'', Tatarinov * Diademodontids ** '' Scalenodon boreus'', Tatarinov *

Traversodontid Traversodontidae is an extinct family of herbivorous cynodonts. Traversodonts were primarily Gondwanan, with many species known from Africa and South America. Recently, traversodonts have also been found from Europe and North America. Traversodon ...

s ** '' Antecosuchus ochevi'', Tatarinov * Therapsids ** '' Calleonasus furvus'' ** '' Cristonasus koltaeviensi'' ** '' Elatosaurus facetus'' ** '' Nasoplanites danilovi'' ** '' Parvobestiola bashkiriensis'' ** '' Rabidosaurus cristatus'' ** '' Rhadiodromus klimovi'' *

Fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

** '' Ceratodus bucobaensis'', '' C. recticristatus'' *

Archosaurs Archosauria () or archosaurs () is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only extant taxon, extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistics ...

** '' Dongusuchus efremovi'', Sennikov

References

{{Reflist Geologic formations of Russia Triassic System of Europe Triassic Russia Anisian Stage Sandstone formations Shale formations Conglomerate formations Fluvial deposits Deltaic deposits Paleontology in Russia Formations

Fossil content

See also

References