Plateosauria is a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

sauropodomorph Sauropodomorpha ( ; 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 lon ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s which lived during the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

to the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

. The name Plateosauria was first coined by Gustav Tornier in 1913. The name afterwards fell out of use until the 1980s.

Classification

Plateosauria is a

node-based taxon Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which ...

. In 1998,

Paul Sereno Paul Callistus Sereno (born October 11, 1957) is a professor of paleontology at the University of Chicago and a National Geographic "explorer-in-residence" who has discovered several new dinosaur species on several continents, including at sites ...

defined Plateosauria as the

last common ancestor In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...

of ''

Plateosaurus engelhardti ''Plateosaurus'' (probably meaning "broad lizard", often mistranslated as "flat lizard") is a genus of Plateosauridae, plateosaurid dinosaur that lived during the Late Triassic Period (geology), period, around 214 to 204 timeline of the evolution ...

'' and ''

Massospondylus carinatus ''Massospondylus'' ( ; from Greek, (massōn, "longer") and (spondylos, "vertebra")) is a genus of sauropodomorph dinosaur from the Early Jurassic. (Hettangian to Pliensbachian ages, ca. 200–183 million years ago). It was described by Si ...

'', and its descendants.

Peter Galton Peter Malcolm Galton (born 14 March 1942 in London) is a British vertebrate paleontologist who has to date written or co-written about 190 papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosa ...

and

Paul Upchurch Paul may refer to: *Paul (given name), a given name (includes a list of people with that name) *Paul (surname), a list of people People Christianity * Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...

in 2004 used a different definition: the last common ancestor of ''Plateosaurus engelhardti'' and ''

Jingshanosaurus xinwaensis ''Jingshanosaurus'' (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period 201.3 million years ago that went extinct 199.3 million years ago in the Hettangian Age. Its maximum weight was around 4.3 t ...

'', and its descendants. In their

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis the Plateosauria belonged to the Prosauropoda, and included the

Plateosauridae Plateosauridae is a family of plateosaurian sauropodomorphs from the Late Triassic of Europe, Greenland, Africa and Asia. Although several dinosaurs have been classified as plateosaurids over the years, the family Plateosauridae is now restric ...

subgroup. In Galton's and Upchurch's study also ''

Coloradisaurus ''Coloradisaurus'' (meaning "Los Colorados lizard") is a genus of massospondylid sauropodomorph dinosaur. It lived during the Late Triassic period ( Norian stage) in what is now La Rioja Province, Argentina. It is known from two specimens col ...

'', ''

Euskelosaurus ''Euskelosaurus'' ("good leg lizard") is a sauropodomorph dinosaur from the Late Triassic of South Africa and Lesotho. Fossils have only been recovered from the lower Elliot Formation in South Africa and Lesotho, and in one locality in Zimbabwe. ...

'', ''

Jingshanosaurus ''Jingshanosaurus'' (meaning "Jingshan lizard") is a genus of sauropodomorph dinosaurs from the early Jurassic period 201.3 million years ago that went extinct 199.3 million years ago in the Hettangian Age. Its maximum weight was around 4.3 t ...

'', ''

Massospondylus ''Massospondylus'' ( ; from Greek, (massōn, "longer") and (spondylos, "vertebra")) is a genus of sauropodomorph dinosaur from the Early Jurassic. (Hettangian to Pliensbachian ages, ca. 200–183 million years ago). It was described by S ...

'', ''

Mussaurus ''Mussaurus'' (meaning " mouse lizard") is a genus of herbivorous sauropodomorph dinosaur that lived in southern Argentina during the Early Jurassic, with a maximum age of 192.78 ± 0.14 Ma. It receives its name from the small size of the sk ...

'', ''

Sellosaurus ''Plateosaurus'' (probably meaning "broad lizard", often mistranslated as "flat lizard") is a genus of plateosaurid dinosaur that lived during the Late Triassic period, around 214 to 204 million years ago, in what is now Central and Northern Eu ...

'', and ''

Yunnanosaurus ''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-buil ...

'' proved to be plateosaurians. However, recent

analyses suggest that the Prosauropoda as traditionally defined is

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

s. Prosauropoda, as currently defined, is a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

as both contain the same taxa by definition. The most recent phylogenetic analysis recovered ''

Issi ''Issi'' (meaning "cold" in Greenlandic) is a plateosaurid dinosaur described in 2021 from the Late Triassic Fleming Fjord Formation of Greenland. It contains one species, ''Issi saaneq''; the full binomial name means "cold bones". Fossils of ...

'' and ''

Plateosaurus ''Plateosaurus'' (probably meaning "broad lizard", often mistranslated as "flat lizard") is a genus of plateosaurid dinosaur that lived during the Late Triassic period, around 214 to 204 million years ago, in what is now Central and Northern Eur ...

'' as the basal-most plateosaurs. The following

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

simplified after an analysis presented by Apaldetti and colleagues in 2011. The following

simplified after an analysis presented by Blair McPhee and colleagues in 2014.

References

Sauropodomorphs {{Sauropodomorph-stub