Diplodocoidea is a superfamily of sauropod

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 included some of the longest animals of all time, including slender giants like '' Supersaurus'', ''

Diplodocus ''Diplodocus'' (, , or ) was a genus of diplodocid sauropod dinosaurs, whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a neo-Latin term derived from Greek δι� ...

'', ''

Apatosaurus ''Apatosaurus'' (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, ''A. ajax'', in 1877, ...

'', and '' Amphicoelias''. Most had very long necks and long, whip-like tails; however, one family (the

dicraeosaurid Dicraeosauridae is a family of diplodocoid sauropods who are the sister group to Diplodocidae. Dicraeosaurids are a part of the Flagellicaudata, along with Diplodocidae. Dicraeosauridae includes genera such as ''Amargasaurus'', ''Suuwassea'', ' ...

s) are the only known sauropods to have re-evolved a short neck, presumably an adaptation for feeding low to the ground. This adaptation was taken to the extreme in the highly specialized sauropod ''

Brachytrachelopan ''Brachytrachelopan'' is a short-necked sauropod dinosaur from the Late Jurassic ( Oxfordian to Tithonian) of Argentina. The holotype and only known specimen (Museo Paleontológico Egidio Feruglio MPEF-PV 1716) was collected from an erosion ...

''. A study of snout shape and dental microwear in diplodocoids showed that the square snouts, large proportion of pits, and fine subparallel scratches in ''Apatosaurus'', ''Diplodocus'', ''Nigersaurus'', and ''Rebbachisaurus'' suggest ground-height nonselective browsing; the narrow snouts of ''Dicraeosaurus'', ''Suuwassea'', and ''Tornieria'' and the coarse scratches and gouges on the teeth of ''Dicraeosaurus'' suggest mid-height selective browsing in those taxa.John A. Whitlock (6 April 2011
Inferences of Diplodocoid (Sauropoda: Dinosauria) Feeding Behavior from Snout Shape and Microwear Analyses
/ref> This taxon is also noteworthy because diplodocoid sauropods had the highest tooth replacement rates of any vertebrates, as exemplified by ''

Nigersaurus ''Nigersaurus'' is a genus of rebbachisaurid sauropod dinosaur that lived during the middle Cretaceous period, about 115 to 105 million years ago. It was discovered in the Elrhaz Formation in an area called Gadoufaoua, in Niger. Fossils of th ...

'', which had new teeth erupting every 30 days. Most diplodocoids belong to Diplodocimorpha, a name first used by Calvo & Salgado (1995), who defined it as "''Rebbachisaurus tessonei'' sp. nov., Diplodocidae, and all descendants of their common ancestor." The group was not used often, and was synonymized with Diplodocoidea as the groups were often found to have the same content. In 2005, Mike P. Taylor and

Darren Naish Darren William Naish is a British vertebrate palaeontologist, author and science communicator. As a researcher, he is best known for his work describing and reevaluating dinosaurs and other Mesozoic reptiles, including '' Eotyrannus'', '' Xenop ...

reviewed diplodocoid phylogeny and taxonomy, and realized that Diplodocimorpha could not be synonymized with Diplodocoidea. Whereas the former was defined node-based, the latter was branch-based. ''

Haplocanthosaurus ''Haplocanthosaurus'' (meaning "simple spined lizard") is a genus of intermediate sauropod dinosaur. Two species, ''H. delfsi'' and ''H. priscus'', are known from incomplete fossil skeletons. It lived during the late Jurassic period (Kimmeridgia ...

'' and possibly '' Amphicoelias'' are non-diplodocimorph diplodocoids.

Taxonomy

The below taxonomy follows the study of Emanuel Tschopp, Octavio Mateus and Roger Benson, 2015: *Diplodocoidea **''

'' **Diplodocimorpha ***

Rebbachisauridae Rebbachisauridae is a family of sauropod dinosaurs known from fragmentary fossil remains from the Cretaceous of South America, Africa, North America, Europe and possibly Central Asia. Taxonomy In 1990 sauropod specialist Jack McIntosh included t ...

***

Flagellicaudata Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae. Phylogeny The clade Flagellicaudata was erected by Harris and Dodson (2004) for the diplodocoid clade formed ...

****

Dicraeosauridae Dicraeosauridae is a family of diplodocoid sauropods who are the sister group to Diplodocidae. Dicraeosaurids are a part of the Flagellicaudata, along with Diplodocidae. Dicraeosauridae includes genera such as '' Amargasaurus'', '' Suuwassea' ...

****

Diplodocidae Diplodocids, or members of the family Diplodocidae ("double beams"), are a group of sauropod dinosaurs. The family includes some of the longest creatures ever to walk the Earth, including ''Diplodocus'' and ''Supersaurus'', some of which may have ...

*****'' Amphicoelias'' ***** Apatosaurinae ***** Diplodocinae The phylogenetics of Diplodocoidea were reviewed in 2015 with a specimen-level phylogenetic analysis, as well as a species-level analysis. Their cladistic analysis is shown below.

References

{{Taxonbar, from=Q132904 Neosauropoda