Microchampsa

Last updated

Microchampsa
Temporal range: Early Jurassic
Scientific classification
Kingdom:
Phylum:
Class:
Superorder:
Suborder:
Genus:
Microchampsa

Young, 1951
Species
  • M. scutataYoung, 1951 (type)

Microchampsa is an extinct genus of protosuchian crocodyliform that existed during the Early Jurassic. Fossils have been found from stratum 6 of the Dahuangtian locality, an outcrop of the Lower Red Beds of the Lufeng Formation in Yunnan, China. [1]

Contents

Description

Parts of the postcranial skeleton, such as the dorsal osteoderms, vertebrae, ribs, and bones of the manus, are known. [2] The dorsal osteoderms of the lumbar region are fused to double headed ribs. All osteoderms are rectangular and overlap each other. [1]

History

Microchampsa was named in 1951 on the basis of an incomplete skeleton consisting of cervical and anterior dorsal vertebrae as well as ribs and three rows of dorsal osteoderms. [2] Three other specimens of crocodylomorphs described in 1965 also seemed to display three rows of osteoderms, and as a result were assigned to the genus Microchampsa. [3] However, later studies revealed that the specimens had only two rows of osteoderms that more closely resembled those of the genus Platyognathus , and that the presence of three rows of osteoderms in the holotype of Microchampsa may have been an artifact of preservation. [4] However, this hypothesis is speculative as the holotype of Microchampsa had since been lost by the time of the studies. [5]

Taxonomy

It was assigned to the suborder Protosuchia in 1965 and the family Notochampsidae in 1992. [3] However, later studies argued that it is a nomen dubium due to the lack of diagnostic material in the incompletely known remains. [6] Thus it can only be regarded as a poorly known protosuchian.

Related Research Articles

<i>Scelidosaurus</i> Genus of reptiles (fossil)

Scelidosaurus is a genus of herbivorous armoured ornithischian dinosaur from the Jurassic of England.

<i>Saichania</i> Extinct genus of dinosaurs

Saichania is a genus of herbivorous ankylosaurid dinosaur from the Late Cretaceous period of Mongolia and China.

<i>Yunnanosaurus</i> Extinct genus of dinosaurs

Yunnanosaurus is an extinct genus of sauropodomorph dinosaur that lived approximately 199 to 183 million years ago in what is now the Yunnan Province, in China, for which it was named. Yunnanosaurus was a large sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could also walk bipedally, and ranged in size from 7 meters (23 feet) long and 2 m (6.5 ft) high to 4 m (13 ft) high in the largest species.

<i>Sinosaurus</i> Genus of dinosaurs

Sinosaurus is an extinct genus of theropod dinosaur which lived during the Early Jurassic Period. It was a bipedal carnivore similar to Dilophosaurus, with proportionally large limbs to its slender body. Fossils of the animal were found at the Lufeng Formation, in the Yunnan Province of China.

Dracopelta is a monospecific genus of ankylosaur dinosaur from Portugal that lived during the Late Jurassic in what is now the Lourinhã Formation. The type and only species is Dracopelta zbyszewskii, which is represented by a partial skeleton including unpublished material.

<i>Gracilisuchus</i> Genus of fossil reptiles

Gracilisuchus is an extinct genus of tiny pseudosuchian from the Late Triassic of Argentina. It contains a single species, G. stipanicicorum, which is placed in the clade Suchia, close to the ancestry of crocodylomorphs. Both the genus and the species were first described by Alfred Romer in 1972.

<i>Doswellia</i> Extinct genus of reptiles

Doswellia is an extinct genus of archosauriform from the Late Triassic of North America. It is the most notable member of the family Doswelliidae, related to the proterochampsids. Doswellia was a low and heavily built carnivore which lived during the Carnian stage of the Late Triassic. It possesses many unusual features including a wide, flattened head with narrow jaws and a box-like rib cage surrounded by many rows of bony plates. The type species Doswellia kaltenbachi was named in 1980 from fossils found within the Vinita member of the Doswell Formation in Virginia. The formation, which is found in the Taylorsville Basin, is part of the larger Newark Supergroup. Doswellia is named after Doswell, the town from which much of the taxon's remains have been found. A second species, D. sixmilensis, was described in 2012 from the Bluewater Creek Formation of the Chinle Group in New Mexico; however, this species was subsequently transferred to a separate doswelliid genus, Rugarhynchos. Bonafide Doswellia kaltenbachi fossils are also known from the Chinle Formation of Arizona.

<i>Mahajangasuchus</i> Extinct genus of reptiles

Mahajangasuchus is an extinct genus of crocodyliform which had blunt, conical teeth. The type species, M. insignis, lived during the Late Cretaceous; its fossils have been found in the Maevarano Formation in northern Madagascar. It was a fairly large predator, measuring up to 4 metres (13 ft) long.

Pedeticosaurus is an extinct genus of crocodylomorph from the Clarens Formation of South Africa. The type species Pedeticosaurus leviseuri was named by Egbert Cornelis Nicolaas van Hoepen in 1915 on the basis of a mold of a mostly complete skeleton found in a quarry near Rosendal, Free State. The mold preserves most of the right half of the skeleton including the skull, ribs, dorsal vertebrae, forelimbs and hindlimbs, but not the tail. It is currently housed in the National Museum in Bloemfontein and cataloged as NMQR606.

<i>Eutretauranosuchus</i> Extinct genus of reptiles

Eutretauranosuchus is an extinct genus of goniopholidid crocodyliform. E. delfsi is the only known species within the genus.

<i>Shidaisaurus</i> Extinct genus of dinosaurs

Shidaisaurus is a genus of metriacanthosaurid dinosaur. Its fossil was found in early Middle Jurassic-age rocks of the Chuanjie Formation in Yunnan, China. It is known from a partial skeleton, holotype DML-LCA 9701-IV, found at the bottom of an assemblage of nine dinosaur individuals, lacking most of the tail vertebrae, ribs, pectoral girdle, and limb bones. Shidaisaurus was described in 2009 by Wu and colleagues. The type species is Shidaisaurus jinae. Generic name and specific name in combination refer to the Jin-Shidai Company that oversaw excavation and inspection of the Jurassic World Park near the site.

<i>Dibothrosuchus</i> Extinct genus of reptiles

Dibothrosuchus is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from several partial skeletons and skulls. These fossils were found in Lower Jurassic rocks of Yunnan, China. Dibothrosuchus was a small terrestrial crocodylomorph that probably had a keen sense of hearing, and thus was probably a vocal animal like modern crocodilians.

<i>Platyognathus</i> Extinct genus of reptiles

Platyognathus is an extinct genus of protosuchian crocodyliform. Fossils are known from the Early Jurassic Lower Lufeng Formation in Yunnan, China and belong to the type and only species, P. hsui.

<i>Tarjadia</i> Extinct genus of reptiles

Tarjadia is an extinct genus of erpetosuchid pseudosuchian, distantly related to modern crocodilians. It is known from a single species, T. ruthae, first described in 1998 from the Middle Triassic Chañares Formation in Argentina. Partial remains have been found from deposits that are Anisian-Ladinian in age. Long known mostly from osteoderms, vertebrae, and fragments of the skull, specimens described in 2017 provided much more anatomical details and showed that it was a fairly large predator. Tarjadia predates known species of aetosaurs and phytosaurs, two Late Triassic groups of crurotarsans with heavy plating, making it one of the first heavily armored archosaurs. Prior to 2017, most studies placed it outside Archosauria as a member of Doswelliidae, a family of heavily armored and crocodile-like archosauriforms. The 2017 specimens instead show that it belonged to the Erpetosuchidae.

<i>Sinosaurosphargis</i> Extinct genus of reptiles

Sinosaurosphargis is an extinct genus of basal marine saurosphargid reptile known from the Middle Triassic Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a single species, Sinosaurosphargis yunguiensis.

Largocephalosaurus is an extinct genus of basal saurosphargid, a marine reptile known from the Middle Triassic Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a type species, Largocephalosaurus polycarpon, and a second species L. qianensis.

Jaxtasuchus is an extinct genus of armored doswelliid archosauriform reptile known from the Middle Triassic of the Erfurt Formation in Germany. The type species, Jaxtasuchus salomoni, was named in 2013 on the basis of several incomplete skeletons and other isolated remains. Like other doswelliids, members of the genus were heavily armored, with four longitudinal rows of bony plates called osteoderms covering the body. Jaxtasuchus is the first doswelliid known from Europe and is most closely related to Doswellia from the Late Triassic of the eastern United States. However, it was not as specialized as Doswellia, retaining several generalized archosauriform characteristics and having less armor. Jaxtasuchus fossils have been found in aquatic mudstones alongside fossils of temnospondyl amphibians, crustaceans, and mollusks, suggesting that Jaxtasuchus was semiaquatic like modern crocodilians.

<span class="mw-page-title-main">Saurosphargidae</span> Extinct family of reptiles

Saurosphargidae is an extinct family of marine reptiles known from the Early Triassic and early Middle Triassic of Europe and China.

<i>Xingxiulong</i> Extinct genus of reptiles

Xingxiulong is a genus of bipedal sauropodiform from the Early Jurassic of China. It contains a single species, X. chengi, described by Wang et al. in 2017 from three specimens, two adults and an immature individual, that collectively constitute a mostly complete skeleton. Adults of the genus measured 4–5 metres (13–16 ft) long and 1–1.5 metres tall. Phylogenetic analysis suggests that Xingxiulong is most closely related to its contemporary Jingshanosaurus, although an alternative position outside of both the Sauropodiformes and Massospondylidae is also plausible.

<i>Invictarx</i> Extinct genus of dinosaurs

Invictarx is a monospecific genus of nodosaurid dinosaur from New Mexico that lived during the Late Cretaceous in what is now the upper Allison Member of the Menefee Formation. The type and only species, Invictarx zephyri, is known from three isolated, incomplete postcranial skeletons. It was named in 2018 by Andrew T. McDonald and Douglas G. Wolfe. Invictarx shares similarities with Glyptodontopelta from the Naashoibito member of the Ojo Alamo Formation, New Mexico.

References

  1. 1 2 Lucas, S. G. (2001). Chinese fossil vertebrates. Columbia University Press, 375 pp.
  2. 1 2 Young, C. C. (1951). The Lufeng saurischian fauna in China. Palaeontologia Sinica, New Series C13:1-96.
  3. 1 2 Simmons, D. J. (1965). The non-therapsid reptiles of the Lufeng Basin, Yunnan, China. Fieldiana: Geology15(1):1-93.
  4. Clark, J. A. (1986). Phylogenetic relationships of the crocodylomorph archosaurs. Ph. D. dissertation. University of Chicago, Chicago. 1-556.
  5. Luo, Z. and Wu, X.-C. (1994). The small tetrapods of the lower Lufeng Formation, Yunnan, China. In: Fraser, F. C. and Sues, H.-D. In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods Cambridge University Press, pp. 251-270.
  6. Wu, X. C. and Sues, H. D. (1995) Protosuchia (Archosauria: Crocodyliformes) from China. In: Sun, A. and Yuanqing, W. (eds.) Sixth Symposium on Mesozoic Terrestrial Ecosystems and Biota, Short Papers. Beijing. China Ocean Press, 57-62.