Anchisauria is an extinct clade of

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 l ...

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 that lived from 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 name Anchisauria was first used Haekel and defined by Galton and Upchurch in the second edition of ''The Dinosauria''. It 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 c ...

containing the

most recent 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 '' Anchisaurus polyzelus'' and ''

Melanorosaurus readi ''Melanorosaurus'' (meaning "Black Mountain Lizard", from the Ancient Greek, Greek ''melas/'', "black", ''oros/'', "mountain" + ''/'', "lizard") is a genus of basal (phylogenetics), basal sauropodomorpha, sauropodomorph dinosaur that lived durin ...

'', and all its descendants. Galton and Upchurch assigned a family of dinosaurs to the Anchisauria: the Melanorosauridae. The more common prosauropods ''

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 Eu ...

'' and ''

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 ...

'' were placed in the sister clade

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. Classificat ...

. However, research has since indicated that ''Anchisaurus'' is closer to

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 ...

s than traditional prosauropods; thus, Anchisauria would by definition also include Sauropoda. 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 ...

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

References

Sources

* Galton, P. M. & Upchurch, P. (2004). "Prosauropoda". In D. B. Weishampel, P. Dodson, & H. Osmólska (eds.), ''The Dinosauria'' (second edition). University of California Press, Berkeley 232–258. * Yates, Adam M. (2007), "The first complete skull of the Triassic dinosaur ''Melanorosaurus'' Haughton (Sauropodomorpha: Anchisauria)", in Barrett, Paul M. & Batten, David J., ''Special Papers in Palaeontology'', vol. 77, pp. 9–55, Sauropodomorphs Norian first appearances Maastrichtian extinctions Tetrapod unranked clades {{sauropodomorph-stub