Mnyamawamtuka

Mnyamawamtuka (pronounced Mm-nya-ma-wah-mm-too-ka; meaning "beast of the Mtuka river drainage" in Kiswahili) is a genus of lithostrotian titanosaur dinosaur from the Late Cretaceous Galula Formation in Tanzania. The type and only species is M. moyowamkia.[1]

Mnyamawamtuka
Temporal range: Early to Late Cretaceous, Aptian to Cenomanian
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Sauropodomorpha
Clade: Sauropoda
Clade: Titanosauria
Clade: Lithostrotia
Genus: Mnyamawamtuka
Gorscak and O'Connor, 2019
Type species
Mnyamawamtuka moyowamkia
Gorscak and O'Connor, 2019

Discovery and naming

In 2004, a sauropod skeleton was found at the Mtuka River, twenty kilometres from Lake Rukwa. It was excavated between 2005 and 2008.[1]

In 2019, the type species Mnyamawamtuka moyowamkia was named and described by Eric Gorscak and Patrick M. O’Connor. The generic name is a contraction of the Kiswahili Mnyama wa Mtuka, the "Beast of the Mtuka". The describers made explicit that they considered "beast" to be an apt name for a member of the Titanosauria. The specific name is a contraction of moyo wa mkia, meaning the "heart of the tail" in Kiswahili, a reference to the heart-shaped cross-section of the rear facet of the middle tail vertebrae.[1]

The holotype, RRBP 05834, was found in a layer of the Mtuka Member of the Galula Formation dating from the Aptian-Cenomanian, most likely between 110 and 100 million years old. It consists of a partial skeleton lacking the skull. It contains a neural arch of a front neck vertebra, centra of four neck vertebrae, seven back vertebrae, seven neural arches and seven centra of tail vertebrae, four chevrons, numerous rib pieces, a right shoulder blade, a right breastbone, both humeri, a left ulna, a right first metacarpal, a left third metacarpal, the left ischium, the right pubic bone, both thighbones, both shinbones, the left calfbone, the left metatarsus, two toe phalanges and a foot claw. The skeleton was not articulated. Despite the missing skull it represents one of the most complete known skeletons of early titanosaurs.[1]

Description

The holotype individual had an estimated length of 7.6 metres and a weight of 1.5 tonnes. It probably was not fully grown.[2]

The describing authors indicated some distinguishing traits. Five of these are autapomorphies, unique derived characters. The middle and rear dorsal (back) vertebrae have an accessory ridge or lamina, forked at the top, located between the normal ridge connecting the front articular processes, and the neural channel. The rear back vertebrae lack a ridge connecting the rear articular processes because the ridge on the rear of the neural process runs all the way down to the neural channel. The middle tail vertebrae have a vertebral body of which the rear face is widened to above and sideways, resulting in a heart-shape. The upper inner side of the front edge of the shoulder blade, the part touching the coracoid, features a curved crest running parallel to a groove. Each of the paired breast bone plates is exceptionally small, equalling just 42% of the length of the humerus.[1]

Phylogeny

Mnyamawamtuka was placed in the Titanosauria in 2019. Cladistic analyses indicated several possible positions in the evolutionary tree. Mnyamawamtuka was sometimes recovered outside of the Lithostrotia. Alternatively, it was positioned in a basal position within the lithostrotians, as sister species of Malawisaurus.[1]

References

  1. ^ a b c d e f Gorscak, Eric; O’Connor, Patrick M. (2019). "A new African titanosaurian sauropod dinosaur from the middle Cretaceous Galula Formation (Mtuka Member), Rukwa Rift Basin, southwestern Tanzania". PLoS ONE. 2 (14): e0211412. doi:10.1371/journal.pone.0211412. PMC 6374010.
  2. ^ https://www.livescience.com/64762-new-titanosaur-heart-shaped-tail.html
Brasilotitan

Brasilotitan is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous (early Maastrichtian) Adamantina Formation of Brazil. The type species is Brasilotitan nemophagus.

Cetiosauridae

Cetiosauridae is a family of sauropod dinosaurs. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural clade. Additionally, at least one study has suggested that the mamenchisaurids may represent a sub-group of the cetiosaurids, which would be termed Mamenchisaurinae.

Daxiatitan

Daxiatitan is a genus of titanosaur dinosaur from the Lower Cretaceous of Lanzhou Basin, Gansu Province, northwestern China. It is known from fossils including several neck vertebrae, a shoulder blade, and a thigh bone.It was a very large dinosaur, estimated at 23–30 meters (75–98 feet). Like both Euhelopus and Huanghetitan, it had an enormously long neck.

Diplodocinae

Diplodocinae is an extinct subfamily of diplodocid sauropods that existed from the Late Jurassic to Early Cretaceous of North America, Europe and South America, about 161.2 to 136.4 million years ago. Genera within the subfamily include Tornieria, Supersaurus, Leinkupal, Galeamopus, Diplodocus, Kaatedocus and Barosaurus.Cladogram of the Diplodocidae after Tschopp, Mateus, and Benson (2015).

Eomamenchisaurus

Eomamenchisaurus (meaning "dawn Mamenchisaurus") is a genus of mamenchisaurid sauropod dinosaur from the Middle Jurassic of Yuanmou, Yunnan, China. The type species is E. yuanmouensis, described by Lü Junchang et al. in 2008.

Ferganasaurus

Ferganasaurus was a genus of dinosaur first formally described in 2003 by Alifanov and Averianov. The type species is Ferganasaurus verzilini. It was a sauropod similar to Rhoetosaurus. The fossils were discovered in 1966 in Kyrgyzstan from the Balabansai Formation and date to the Callovian stage of the Middle Jurassic.

Flagellicaudata

Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae.

Gravisauria

Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.

Huangshanlong

Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.

Jiutaisaurus

Jiutaisaurus is a genus of sauropod dinosaur from the Quantou Formation of China. Jiutaisaurus was a sauropod which lived during the Cretaceous. The type species, Jiutaisaurus xidiensis, was described by Wu et al. in 2006, and is based on eighteen vertebrae.

Kaijutitan

Kaijutitan (meaning "Kaiju titan" after the type of Japanese movie monsters) is a genus of basal titanosaur dinosaur from the Sierra Barrosa Formation from Neuquén Province in Argentina. The type and only species is Kaijutitan maui.

Lithostrotia

Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Unchurch et al. in 2004 as the most recent common ancestor of Malawisaurus and Saltasaurus and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek lithostros, meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch et al. include caudal vertebrae with strongly concave front faces (procoely), although the farthest vertebrae are not procoelous.

Microcoelus

Microcoelus is a dubius genus of small Titanosaurian sauropod dinosaur native to Argentina. It is known from only a single dorsal vertebra. A left humerus was formerly referred to this species, but it is now considered to belong to Neuquensaurus. This species may be a synonym of the contemporary sauropod Neuquensaurus australis.It was described by British paleontologist Richard Lydekker in 1893.

Oceanotitan

Oceanotitan is a genus of titanosauriform sauropod known from the Upper Jurassic Praia da Amoreira-Porto Novo Formation of Portugal. It contains one species, Oceanotitan dantasi.The holotype consists of the scapula, almost all of the pelvis, a complete leg sans the toes, and nine caudals.

Pilmatueia

Pilmatueia is a diplodocoid sauropod belonging to the family Dicraeosauridae that lived in Argentina during the Early Cretaceous.

Tambatitanis

Tambatitanis is an extinct genus of titanosauriform dinosaur from the Early Cretaceous (probably early Albian) of Japan. It is known from a single type species, Tambatitanis amicitiae. It was probably around 14 meters long and its mass was estimated at some 4 tonnes. It was a basal titanosauriform and possibly belonged to the Euhelopodidae.

Tastavinsaurus

Tastavinsaurus is a genus of sauropod dinosaur belonging to the Titanosauriformes. It is based on a partial skeleton from the Early Cretaceous of Spain. The type species is Tastavinsaurus sanzi, named in honor of the Rio Tastavins in Spain and Spanish paleontologist José Luis Sanz.

Tengrisaurus

Tengrisaurus (meaning "Tengri lizard") is a genus of lithostrotian sauropod, from the Early Cretaceous (Barremian-Aptian), of the Murtoi Formation, Russia. It was described in 2017 by Averianov & Skutschas. The type species is T. starkovi.

Vulcanodontidae

The Early Jurassic sauropod dinosaurs Zizhongosaurus, Barapasaurus, Tazoudasaurus, and Vulcanodon may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by M.R. Cooper in 1984. In 1995 Hunt et al. published the opinion that the family is synonymous with the Barapasauridae. One of the key morphological features specific to the family is an unusually narrow sacrum.

Languages

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.