Zhyrasuchus Temporal range: Late Cretaceous | |
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Genus: | Zhyrasuchus Nesov et al., 1989 |
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Zhyrasuchus is an extinct monospecific genus of crocodylomorph that may have been a crocodylid eusuchian, but is only known from scanty material including a frontal (one of the bones of the roof of the skull). Its fossils were found in the Coniacian-age Upper Cretaceous Bissekty Formation of Dzharakhuduk, Uzbekistan. Zhyrasuchus was described in 1989 by Lev Nesov and colleagues. The type species is Z. angustifrons. A 2000 review by Glenn Storrs and Mikhail Efimov could not determine how Zhyrasuchus and the contemporaneous Tadzhikosuchus were related, or even if they were synonyms, due to the poor fossils available. [1]
The Kyzylkum Desert is the 15th largest desert in the world. Its name means Red Sand in Turkic languages. It is located in Central Asia, in the land between the confluent rivers Amu Darya and Syr Darya, a region historically known as Transoxania. Today it is divided between Kazakhstan, Turkmenistan and Uzbekistan. It covers about 298,000 km2 (115,000 sq mi).
Ophthalmosaurus is an ichthyosaur of the Jurassic period. Possible remains from the Cretaceous, around 145 million years ago, are also known. Named for its extremely large eyes, it had a 6 metres (20 ft) long dolphin-shaped body with jaws containing many small but robust teeth. Major fossil finds of this genus have been recorded in Europe with a second species possibly being found in North America.
Shamosuchus is an extinct genus of neosuchian crocodyliform that lived during the Late Cretaceous (Campanian) period in what is now the Djadokhta Formation of Mongolia, approximately 75 million to 71 million years ago.
Plutoniosaurus is an extinct genus of ophthalmosaurid ichthyosaur from the Early Cretaceous of the vicinity of Ulyanovsk, European Russia.
Peipehsuchus is an extinct genus of metriorhynchoid crocodyliform from the Early Jurassic (Toarcian). The type species, P. teleorhinus, is known from China and fragmentary remains were found in the Callovian of Kyrgyzstan. The type specimen is known only by a fragmentary rostrum and teeth, and was originally believed to be a teleosaurid. A complete teleosaurid skull was referred to Peipehsuchus, however, the type specimen of Peipehsuchus has since been determined to be a metriorhynchoid and so the skull cannot belong to it.
Undorosaurus is an extinct genus of ophthalmosaurid ichthyosaur known from western Russia, Svalbard, and Poland.
Zholsuchus is a genus of crocodyliform that may have been a goniopholidid mesoeucrocodylian, but is only known from scanty material. This specimen was found in the Coniacian-age Upper Cretaceous Bissekty Formation of Dzharakhuduk, Uzbekistan. Zholsuchus was described in 1989 by Lev Nesov and colleagues. The type species is Z. procevus. A 2000 review by Glenn Storrs and Mikhail Efimov designated Zholsuchus a dubious name.
Kansajsuchus is an extinct genus of paralligatorid mesoeucrocodylian. It is based on PIN 2399/301, a right premaxilla, one of the bones of the tip of the snout. This specimen was found in rocks of the lower Santonian-age Upper Cretaceous Yalovach Svita of Kansai, in the Fergana Basin of Tajikistan. Additional fossils including vertebrae and bony armor have been assigned to this genus. It would have been a large animal, estimated at up to 8 metres (26 ft) long. Kansajsuchus was described in 1975 by Mikhail Efimov. The type species is Kansajsuchus extensus.
Tadzhikosuchus is an extinct genus of neosuchian crocodyliform from the Late Cretaceous of Tajikistan. Three species have been named: the type species T. macrodentis, described by Efimov in 1982 from the lower Santonian-age Upper Cretaceous Ialovachsk Formation of Kansai, Tajikistan, in the Fergana Basin of Tajikistan; T. neutralis from the same location, by Efimov in 1988; and T. kizylkumensis from Turonian-age rocks of the Upper Cretaceous Bissekty Formation of Dzharakhuduk, Uzbekistan, by Nesov and colleagues in 1989. However, a 2000 review by Glenn Storrs and Mikhail Efimov could not differentiate between the species based on their type material, and recommended grouping the specimens of all three species under T. macrodentis. They also could not determine how Tadzhikosuchus and the contemporaneous Zhyrasuchus were related, or even if they were synonyms, due to the poor fossils available. The name of the Tadzhikosuchus is derived from the Russian spelling of the name of the former Soviet republic of Tajikistan.
Nominosuchus is a genus of protosuchian-grade crocodylomorph. It is known from several specimens discovered in ancient lake deposits of the Tithonian-age Upper Jurassic Tsagaantsav Formation, southwestern Mongolia. The type specimen is PIN 4174/4, a partial skull. Nominosuchus was not large; its skull length is estimated at 60 millimetres (2.4 in). It was similar to Shartegosuchus, and is assigned to the same family (Shartegosuchidae). Nominosuchus was described in 1996 by Mikhail Efimov, and the type species is N. matutinus.
Shartegosuchus is a genus of protosuchian-grade crocodylomorph. It is known primarily from PIN 4174/2, the partial deformed skull and jaws of a juvenile. This specimen was discovered in ancient lake deposits of the Tithonian-age Upper Jurassic Tsagaantsav Formation, southwestern Mongolia. The estimated length of the holotype skull is 40 millimetres (1.6 in). This genus was similar to Nominosuchus, and both are assigned to the same family (Shartegosuchidae). Shartegosuchus was described in 1988 by Mikhail Efimov, and the type species is S. asperopalatum.
Turanosuchus is an extinct genus of paralligatorid crocodyliform. It is based on PIN 2229/507, a partial lower jaw consisting of the area where the two halves of the lower jaw meet. This specimen was found in rocks of the lower Santonian-age Upper Cretaceous Bostobe Svita of Shakh-Shakh, southern Kazakhstan. Turanosuchus was described in 1988 by Mikhail Efimov. The type species is T. aralensis. Halliday et al. (2015) revised the material attributed to T. aralensis and concluded that it represents non-diagnostic neosuchian material, and as such the genus was considered to be a nomen dubium.
Karatausuchus is an extinct genus of atoposaurid crocodylomorph. It is known from a single specimen discovered in the Late Jurassic Karabastau Svita from the vicinity of Mikhailovka in the Karatau Mountains of southern Kazakhstan. The type specimen is PIN 25858/1, a complete but poorly preserved juvenile skeleton with some possible soft tissue preservation. It is notable for having over 90 teeth, but its other anatomical details are difficult to discern. The length of this individual is estimated at 160 millimetres (6.3 in). Karatausuchus was described in 1976 by Mikhail Efimov, and the type species is K. sharovi.
Simbirskiasaurus is an extinct genus of ichthyosaur from the Early Cretaceous of Ulyanovsk Oblast, Russia. Its type specimen is YKM 65119, a fragmentary skull and vertebral column.
The Ialovachsk or Yalovach Formation is a geologic formation in Kyrgyzstan, Tajikistan and Uzbekistan dating to the Santonian age of the Cretaceous period.
Irenosaurus is a genus of choristodere, a type of amphibious reptile. It is known from a single fragmentary postcranial skeleton (PIN 3386/2), discovered in the Aptian-age Lower Cretaceous Hühteeg Formation at Hüren Dukh, central Mongolia. The type species is I. egloni, which was originally described as a new species of the related choristodere Tchoiria in 1983 by Efimov. Efimov transferred the species to the new genus Irenosaurus in 1988. Evans and Hecht (1993) questioned the separation of the taxon from Tchoiria namsarai from the same locality on the grounds that the differences between the two may not have been greater than those of various species of the choristodere Champsosaurus. A later review by Efimov and Storrs (2000) retained the two as separate, noting that some characteristics of Irenosaurus are more like Khurendukhosaurus, also known from the same site, at the same time recognizing the difficulties of distinguishing three genera from the same locality. Irenosaurus was a small choristodere, approximately 1 to 1.5 metres long. It is known from what are interpreted as lake deposits.
Khurendukhosaurus is a genus of choristodere, a type of amphibious reptile. It is known from Lower Cretaceous rocks of Mongolia and Russia. Two species have been named. The type species, K. orlovi, was named in 1984 by Sigogneau–Russell and Efimov for the fragmentary postcranial skeleton PIN 3386/3. This specimen was discovered in the Albian-age Lower Cretaceous Khuren Dukh Formation Formation at Hüren Dukh, central Mongolia. The lake deposits at this site also contain fossils of the choristoderes Irenosaurus and Tchoiria. Other postcranial bones of K. orlovi have been found at this site as well.
Tchoiria is a genus of simoedosaurid choristodere, a type of crocodile-like aquatic reptile. Fossils of this genus have been found in Early Cretaceous-age rocks in Mongolia. Four species have been named, but two have been given their own genera. The type species is T. namsari, based on PIN 3386/1, a partial skull and skeleton discovered in the Aptian-age Lower Cretaceous Hühteeg Formation at Hüren Dukh, central Mongolia. Two other species were named from this locality, with both later being reassigned: T. egloni, now Irenosaurus egloni; and T. magnus, now Ikechosaurus magnus. A fourth species, T. klauseni, was named from a partial skull and skeleton found in rocks of roughly the same age farther west in Mongolia.
Pervushovisaurus is a genus of platypterygiine ichthyosaur from the Late Cretaceous of the Saratov region in western Russia and the Cambridge area of the UK. It was originally described as a subgenus of Platypterygius, but later work showed that it was sufficiently distinct from the type species of Platypterygius, P. platydactylus, to be elevated to full generic rank. The type species of Pervushovisaurus, P. bannovkensis, is known only from the holotype, SSU 104a/24, a partial skull. In 2016, an additional species of Platypterygius, P. campylodon, was also referred to Pervushovisaurus.
The Mother’s Day Quarry (MDQ) is a Late Jurassic (Kimmeridgian) fossil site in the Morrison Formation that is located at the base of the Pryor Mountains in Carbon County, Montana. The site was first discovered by the Museum of the Rockies in 1994 and has produced over 2,500 elements since its discovery. Apart from approximately 12 theropod teeth, stegosaur limb material, and two conchostracans found at the site, these elements almost exclusively belong to specimens of the sauropod dinosaur Diplodocus sp. This deposit of fossils is thought to be the result of an age-segregated herd of these dinosaurs congregating at a limited water source and eventually succumbing to drought conditions.