Vladlenosaurus

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Vladlenosaurus
Temporal range: Early Triassic
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Temnospondyli
Suborder: Stereospondyli
Clade: Capitosauria
Genus: Vladlenosaurus
Morkovin and Novikov, 2000
Type species
V. alexeyevi
Morkovin and Novikov, 2000

Vladlenosaurus is an extinct genus of capitosaurian temnospondyl from Russia. It lived during the late Vetlugian (Early Triassic). Based on the type of deposits it was found in, Vladlenosaurus probably inhabited lacustrine, or lake, habitats. The type species is V. alexeyevi, named in 2000.

Contents

Description

Unlike the flatter, more rounded snouts of other capitosaurs, Vladlenosaurus had a wedge-shaped snout. This characteristic is also seen in trematosaurians, although it was independently acquired in both cases as a result of convergent evolution. [1]

Classification

Vladlenosaurus is similar in appearance to the benthosuchids, a group of trematosauroid temnospondyls, but is more closely related to mastodonsauroids. Among capitosaurs, it shares many features with the basal form Wetlugasaurus , also from the Early Triassic of Russia. Vladlenosaurus alexeyevi was even considered to be a species of Wetlugasaurus in a 2006 study. [2] In a 2011 phylogenetic analysis, the first to incorporate Vladlenosaurus, the genus was found to be most closely related to Odenwaldia . [1] It and Odenwaldia formed a basal clade of capitosaurs more derived than Wetlugasaurus, the most basal capitosaur. Below is a modified cladogram from Fortuny et al (in press) showing the relationship of Vladlenosaurus to other stereospondyls: [1]

Stereospondyli  

Related Research Articles

<span class="mw-page-title-main">Temnospondyli</span> Ancestors of modern amphibians adapted to life on land

Temnospondyli or temnospondyls is a diverse ancient order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are amphibians, many had characteristics such as scales and large armour-like bony plates (osteoderms) that generally distinguish them from the modern soft-bodied lissamphibians.

<i>Mastodonsaurus</i> Extinct genus of temnospondyls

Mastodonsaurus is an extinct genus of temnospondyl from the Middle Triassic of Europe. It belongs to a Triassic group of temnospondyls called Capitosauria, characterized by their large body size and presumably aquatic lifestyles. Mastodonsaurus remains one of the largest amphibians known, and may have exceeded 6 meters in length.

<i>Rhinesuchus</i> Extinct genus of temnospondyls

Rhinesuchus is a large temnospondyl. Remains of the genus are known from the Permian of the South African Karoo Basin's Tapinocephalus and Cistecephalus assemblage zones, both belonging to the Beaufort Group. The skull of Rhinesuchus had a flat triangular shape with blunt snout similar to some of the other large temnospondyls, and had a palate filled with small sharp teeth, suggesting that it hunted fish. Also, the small eyes were on top of the head suggesting that it approached its prey from below.

<i>Wetlugasaurus</i> Extinct genus of temnospondyls

Wetlugasaurus is an extinct genus of temnospondyl from the Early Triassic (Olenekian) Charkabozh, Kzylsaiskaya, Petropavlovka, Kamennyi Yar and Vetluga Series Formations of northern Russia and Greenland. It had a 22 centimetres (8.7 in) long skull, and reached a total length of 1 metre.

<i>Eryosuchus</i> Extinct genus of temnospondyls

Eryosuchus is an extinct genus of capitosauroid temnospondyl from the Middle Triassic of northern Russia. It was a very large predator: the largest specimen known could reach up to 3.5 m (11.5 ft) in length, with a skull over 1 m long.

<i>Trematosaurus</i> Extinct genus of amphibians

Trematosaurus is an extinct genus of trematosaurid temnospondyl amphibian found in Germany and Russia. It was first named by Hermann Burmeister in 1849 and the type species is Trematosaurus brauni.

<i>Eocyclotosaurus</i> Extinct genus of temnospondyls

Eocyclotosaurus is an extinct genus of mastodonsauroid temnospondyl from the Middle Triassic (Anisian). The name Eocyclotosaurus means "dawn round-eared lizard". It is characterized as a capitosauroid with a long and slender snout, closed otic fenestra, and small orbits. It measured over one metre and had a 22 cm skull.

<i>Benthosuchus</i> Extinct genus of amphibians

Benthosuchus is an extinct genus of temnospondyl amphibian from the Early Triassic of Russia. It was primarily aquatic, living in rivers and lakes. Multiple species are known, with the largest reaching about 2.5 meters in length.

<span class="mw-page-title-main">Lydekkerinidae</span> Extinct family of temnospondyls

Lydekkerinidae is a family of stereospondyl temnospondyls that lived in the Early Triassic period. During this time period, lydekkerinids were widely distributed, with putative remains reported from Russia, Greenland, India, South Africa, Madagascar, Australia, and Antarctica. In contrast to most other stereospondyls, lydekkerinids were relatively small-bodied. The type genus is Lydekkerina, the namesake of the family and the best-known lydekkerinid.

<span class="mw-page-title-main">Mastodonsauridae</span> Extinct family of temnospondyls

Mastodonsauridae is a family of capitosauroid temnospondyls. Fossils belonging to this family have been found in North America, Greenland, Europe, Asia, and Australia. The family Capitosauridae is synonymous with Mastodonsauridae.

Hyperokynodon is an extinct genus of trematosaurian temnospondyl within the family Trematosauridae. Fossils have been found in Germany. While most trematosaurids existed during the Early Triassic, Hyperokynodon has been found in Late Triassic deposits, making it the youngest known trematosaurid. Hyperokynodon was known since 1852, but it was not identified as a trematosaurid until 1987. The type and only species is H. keuperinus.

Cosgriffius is an extinct genus of trematosaurian temnospondyl within the family Trematosauridae. It was described in 1993 by Samuel P. Welles based on a single partial skull from the well-known Meteor Crater Quarry in Arizona that also produced more abundant remains of the capitosaur Wellesaurus peabodyi. The skull was long and slender, features typically associated with the trematosaurid subfamily Lonchorhynchinae. This is the only trematosaurid known from western North America.

<i>Odenwaldia</i> Extinct genus of temnospondyls

Odenwaldia is an extinct genus of mastodonsauroid temnospondyl within the family Heylerosauridae.

<span class="mw-page-title-main">Capitosauria</span> Extinct clade of amphibians

Capitosauria is an extinct group of large temnospondyl amphibians with simplified stereospondyl vertebrae. Mainly living as piscivores in lakes and rivers, the Capitosauria and its sister taxon Trematosauria were the only major labyrinthodonts that existed during the Mesozoic in ecological niches broadly similar to those of modern crocodiles, and some grew to very large sizes. At 6 meters in length, the Mid-Triassic Mastodonsaurus giganteus is not only thought to have been the largest capitosaur, but possibly also the largest amphibian to have lived. The latest known remains are from the Rhaetian of Germany and are referred to Cyclotosaurus.

<i>Calmasuchus</i> Extinct genus of temnospondyls

Calmasuchus is a genus of capitosaurian temnospondyl which lived during the middle Triassic. Fossils of Calmasuchus have been recovered from the La Mora site of the Catalan basin in Barcelona of Spain. Identified from a partial skull roof and palate, skull fragments and complete hemi-mandible, it was named by Josep Fortuny, Àngel Galobart and Carles De Santisteban in 2011. The type species is Calmasuchus acri.

Procyclotosaurus is an extinct genus of stenotosaurid capitosaurian temnospondyl. The type species is P. stantonensis. In 1904, English paleontologist Arthur Smith Woodward described it as a species of Capitosaurus, C. stantonensis, based on a partial skull known as R 3174. In 1958, the species was assigned to the new genus. It is known from the Lower Keuper, a European stratigraphic unit that was deposited during the late Middle Triassic. Fossils have been found from Staffordshire, England.

<span class="mw-page-title-main">Stenotosauridae</span> Extinct family of temnospondyls

Stenotosauridae is an extinct family of mastodonsauroid temnospondyls. It has included genera such as Stenotosaurus, Wellesaurus, and Procyclotosaurus.

<span class="mw-page-title-main">Heylerosauridae</span> Extinct family of temnospondyls

Heylerosauridae is a family of mastodonsauroid temnospondyls. It was first named in 1980 to include the genera Odenwaldia and Quasicyclotosaurus. In addition to these genera, the family now includes Eocyclotosaurus and Yuanansuchus. Recent phylogenetic analyses have not found a close relationship between Odenwaldia and other heylerosaurids and place it outside the family. Heylerosaurids are generally regarded as the sister taxon of the stenotosaurids.

Tatrasuchus is an extinct genus of temnospondyl from the Middle Triassic of Poland and Germany. It is classified as a member of the family Cyclotosauridae or Mastodonsauridae. It is closely related to the genus Cyclotosaurus. The type species, Tatrasuchus kulczyckii, was named in 1996. Damiani (2001) considered genus Kupferzellia Schoch (1997) from the Middle Triassic of Germany to be a junior synonym of Tatrasuchus, and recombined its type species, K. wildi as the second species of Tatrasuchus. This classification was followed by some authors, e.g. Fortuny et al. (2011); other authors, e.g. Schoch (2008), maintain Tatrasuchus and Kupferzellia as distinct genera. However, Schoch & Moreno (2024) synonymized the two genera, maintaining T. wildi as a distinct species from T. kulczyckii.

Selenocara is an extinct genus of mastodonsauroid temnospondyl. The type species is Selenocara groenlandica, described by Gunnar Säve-Söderbergh in 1935 on the basis of skull bones from the Lower Triassic Wordie Creek Formation of Greenland. Säve-Söderbergh originally described it as a new species of Wetlugasaurus.

References

  1. 1 2 3 Fortuny, Josep; Galobart, À; De Santisteban, C. (2011). "A new capitosaur from the Middle Triassic of Spain and the relationships within the Capitosauria" (PDF). Acta Palaeontologica Polonica. 56 (3): 553–566. doi: 10.4202/app.2010.0025 .
  2. Shishkin, M.A.; Sennikov, A.G; Novikov, I.V.; Ilyina, N.V. (2006). "Differentiation of tetrapod communities and some aspects of biotic events in the early triassic of Eastern Europe". Paleontological Journal. 40 (1): 1–10. doi:10.1134/S0031030106010011. S2CID   129895753.