Editing Mussaurus (section)

{{Short description|Extinct genus of dinosaurs}}
{{Automatic taxobox
| fossil_range = [[Early Jurassic]], <br/> {{Fossil range|Sinemurian}}
| image = Mussaurus patagonikus DSC 2904.jpg
| image_caption = Fossil juvenile skeleton
| parent_authority = Bonaparte & Vince, 1979
| taxon = Mussaurus
| authority = Bonaparte & Vince, 1979
| type_species = {{extinct}}'''''Mussaurus patagonicus'''''
| type_species_authority = Bonaparte & Vince, 1979
}}
'''''Mussaurus''''' (meaning "[[mouse]] [[lizard]]") is a [[genus]] of [[herbivorous]] [[sauropodomorph]] [[dinosaur]] that lived in southern [[Argentina]] during the [[Sinemurian]] stage of the [[Early Jurassic]]. 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. 

In its early stages of life, ''Mussaurus'' was a small [[quadrupedalism|quadrupedal]] herbivore, walking on all four legs. As it grew up, the changes in body proportions may have led its centre of mass to move backwards towards its [[pelvis]]. Adults would have been medium-sized [[bipedalism|bipedal]] herbivores, measuring up to {{convert|8|m|ft}} long and weighing up to {{convert|1.2|-|1.6|MT|ST}}.

Numerous specimens of varying age found in a single locality suggest that ''Mussaurus'' is one of the earliest dinosaurs to have lived in a gregarious lifestyle. With its possible origin from the [[Triassic]], this complex social behaviour may have given rise to the sauropods' early success as the largest herbivores on land. ''Mussaurus'' also possessed anatomical features that suggest a close, possibly transitional evolutionary relationship with true sauropods.