The Massopoda is a clade of sauropodomorph dinosaurs which lived during the Late Triassic to the Late Cretaceous periods. It was named by paleontologist Adam M. Yates of the University of the Witwatersrand in 2007. Massopoda is a stem-based taxon, defined as all animals more closely related to Saltasaurus loricatus than to Plateosaurus engelhardti.
Yates assigned the Massopoda to Plateosauria. Within the clade, he assigned the families Massospondylidae (which includes the relatively well-known dinosaur Massospondylus) and Riojasauridae (which includes Riojasaurus) as well as the Sauropoda.
|Mounted skeleton of Lufengosaurus|
The Anchisauria were a clade of sauropodomorph dinosaurs that lived during the Late Triassic and Early Jurassic. The name Anchisauria was first used by Galton and Upchurch in the second edition of The Dinosauria. Galton and Upchurch assigned two families of dinosaurs to the Anchisauria: the Anchisauridae and the Melanorosauridae. The more common prosauropods Plateosaurus and Massospondylus were placed in the sister clade Plateosauria.
However, recent research indicates that Anchisaurus is closer to sauropods than traditional prosauropods; thus, Anchisauria would also include Sauropoda.The following cladogram simplified after an analysis presented by Blair McPhee and colleagues in 2014.Averostra
Averostra, or "bird snouts", is a clade that includes most theropod dinosaurs that have a promaxillary fenestra (fenestra promaxillaris), an extra opening in the front outer side of the maxilla, the bone that makes up the upper jaw. Two groups of averostrans, the Ceratosauria and the Orionides, survived into the Cretaceous period. When the Cretaceous–Paleogene extinction event occurred, ceratosaurians and two groups of orionideans within the clade Coelurosauria, the Tyrannosauroidea and Maniraptoriformes, were still extant. Only one subgroup of maniraptoriformes, Aves, survived the extinction event and persisted to the present day.Avetheropoda
Avetheropoda, or "bird theropods", is a clade that includes carnosaurians and coelurosaurs to the exclusion of other dinosaurs.Cerapoda
Cerapoda ("ceratopsians and ornithopods") is a clade of the dinosaur order Ornithischia.Chuxiongosaurus
Chuxiongosaurus is a genus of basal sauropodomorph dinosaur which lived during the Early Jurassic Period. Fossils of this genus have been found in the Lower Lufeng Formation, Yunnan Province, southern China. Identified from the holotype CMY LT9401 a nearly complete skull (including a lower jaw) with some similarities to Thecodontosaurus, it was described as the "first basal sauropod dinosaur from the Early Jurassic of China," more basal than Anchisaurus. It was named by Lü Junchang, Yoshitsugu Kobayashi, Li Tianguang and Zhong Shimin in 2010, and the type species is Chuxiongosaurus lufengensis.Gryponyx
Gryponyx (meaning "hooked-claw") is an extinct genus of massopod sauropodomorph known from southern Free State, central South Africa.Ignavusaurus
Ignavusaurus is a genus of basal sauropodomorph dinosaur that lived during the Early Jurassic in what is now Lesotho. Its fossils were found in the Upper Elliot Formation which is probably Hettangian in age (around 200 million years ago). It was described on the basis of a partial, well preserved articulated skeleton. The type species, I. rachelis, was described in 2010 by Spanish palaeontologist F. Knoll.Jingshanosaurus
Jingshanosaurus (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period.Massospondylidae
Massospondylidae is a family of early massopod dinosaurs that existed in Asia, Africa, South America and Antarctica during the Late Triassic to the Early Jurassic periods. Several dinosaurs have been classified as massospondylids over the years. The largest cladistic analysis of early sauropodomorphs, which was presented by Apaldetti and colleagues in November 2011, found Adeopapposaurus, Coloradisaurus, Glacialisaurus, Massospondylus, Leyesaurus and Lufengosaurus to be massospondylids. This result supports many previous analyses that tested fewer taxa. However, this analysis found the two recently described North American massopods, Sarahsaurus and Seitaad, and the South African Ignavusaurus to nest outside Massospondylidae, as opposed to some provisional proposals. Earlier in 2011, Pradhania, a sauropodomorph from India, was tested for the first time in a large cladistic analysis and was found to be a relatively basal massospondylid. Mussaurus and Xixiposaurus may also be included within Massospondylidae. In 2019, a specimen previously assigned to Massospondylus from South Africa was re-examined and found to belong to a separate genus that was named Ngwevu.Mussaurus
Mussaurus (meaning "mouse lizard") is a genus of herbivorous sauropodomorph dinosaur that lived in southern Argentina during the Late Triassic, about 215 million years ago. It receives its name from the small size of the skeletons of juvenile and infant individuals, which were once the only known specimens of the genus. However, since Mussaurus is now known from adult specimens, the name is something of a misnomer; adults possibly reached 6 metres (20 ft) in length and weighed more than 1,000 kilograms (2,200 lb). Mussaurus possesses anatomical features suggesting a close, possibly transitional evolutionary relationship with true sauropods.Orionides
Orionides is a clade of tetanuran theropod dinosaurs from the Middle Jurassic to the Present. The clade includes most theropod dinosaurs, including birds.Plateosauria
Plateosauria is a clade of sauropodomorph dinosaurs which lived during the Late Triassic to the Late Cretaceous. The name Plateosauria was first coined by Gustav Tornier in 1913. The name afterwards fell out of use until the 1980s.
Plateosauria is a node-based taxon. In 1998, Paul Sereno defined Plateosauria as the last common ancestor of Plateosaurus engelhardti and Massospondylus carinatus, and its descendants. Peter Galton and Paul Upchurch in 2004 used a different definition: the last common ancestor of Plateosaurus engelhardti and Jingshanosaurus xinwaensis, and its descendants. In their cladistic analysis the Plateosauria belonged to the Prosauropoda, and included the Plateosauridae subgroup. In Galton's and Upchurch's study also Coloradisaurus, Euskelosaurus, Jingshanosaurus, Massospondylus, Mussaurus, Sellosaurus, and Yunnanosaurus proved to be plateosaurians.However, recent cladistic analyses suggest that the Prosauropoda as traditionally defined is paraphyletic to sauropods. Prosauropoda, as currently defined, is a synonym of Plateosauridae as both contain the same taxa by definition.
The following cladogram simplified after an analysis presented by Apaldetti and colleagues in 2011.
The following cladogram simplified after an analysis presented by Blair McPhee and colleagues in 2014.Plateosauridae
Plateosauridae is a family of plateosaurian sauropodomorphs from the Late Triassic of Europe. Although several dinosaurs have been classified as plateosaurids over the years, the family Plateosauridae is now restricted to Plateosaurus. In another study, Yates (2003) sunk Sellosaurus into Plateosaurus (as P. gracilis).Pulanesaura
Pulanesaura is an extinct genus of basal sauropod known from the Early Jurassic (late Hettangian to Sinemurian) Upper Elliot Formation of the Free State, South Africa. It contains a single species, Pulanesaura eocollum, known from partial remains of at least two subadult to adult individuals.Riojasauridae
Riojasauridae is a family of sauropod-like dinosaurs from the Upper Triassic. It is known primarily from the genera Riojasaurus and Eucnemesaurus. Sites containing Riojasauridae include the Lower Elliot Formation of Orange Free State, South Africa (where fossils of Eucnemesaurus have been found), and Ischigualasto, in La Rioja Province, Argentina ( where fossils of Riojasaurus have been recovered).Sarahsaurus
Sarahsaurus is a genus of basal sauropodomorph dinosaur which lived during the lower Jurassic period in what is now northeastern Arizona, United States.Sauropodomorpha
Sauropodomorpha ( SOR-ə-POD-ə-MOR-fə; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had long necks and tails, were quadrupedal, and became the largest animals to ever walk the Earth. The "prosauropods", which preceded the sauropods, were smaller and were often able to walk on two legs. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the mid-Triassic (approximately 230 Ma) until their decline and extinction at the end of the Cretaceous (approximately 66 Ma).Seitaad
Seitaad is a genus of sauropodomorph dinosaur which lived during the lower Jurassic period in what is now southern Utah, United States.
Seitaad is known from an articulated partial postcranial holotype skeleton referred to as UMNH VP 18040. The skeleton is missing its head, neck and tail. It was collected from the Early Jurassic Navajo Sandstone, the uppermost unit of the Glen Canyon Group, dating to the Pliensbachian stage, near Comb Ridge, San Juan County. A phylogenetic study of Seitaad found it to be a plateosaur sauropodomorph, placing it in Massospondylidae or alternatively (a less probable position) in Plateosauridae, but its placement within the Plateosauria is not well understood. In a cladistic analysis, presented by Apaldetti and colleagues in November 2011, Seitaad was found to be within Massopoda, just outside Anchisauria.Seitaad was first described by Joseph J. W. Sertich and Mark A. Loewen in 2010 and the type species is Seitaad ruessi. The generic name is derived from Séít‘áád (Navajo language), a mythological sand monster from the Diné folklore who buried its victims in dunes. Seitaad appears to have been entombed by the collapse of a sand dune. The specific name honours Everett Ruess, a young artist, poet and naturalist, who mysteriously disappeared in 1934 while exploring southern Utah. Seitaad is the second basal sauropodomorph dinosaur to have been identified in North America.Yunnanosaurus
Yunnanosaurus ( YOO-nan-o-SAWR-əs) is an extinct genus of sauropodomorph dinosaur that lived approximately 201 to 168 million years ago in what is now the Yunnan Province, in China. 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.