Mussaurus

Mussaurus (meaning "mouse lizard") was an early, plant-eating prosauropod dinosaur from the Upper Triassic, about 215 million years ago.  It was found in southern Argentina. It gets its name from the small size of the skeletons first discovered.
They were large-eyed hatchlings (babies), only 9-16 inches long (18-37 cm); these are the smallest dinosaur skeletons yet found.

However, Mussaurus is now known from adult specimens.Otero A. & Pol D. 2013. Postcranial anatomy and phylogenetic relationships of Mussaurus patagonicus (Dinosauria, Sauropodomorpha). Journal of Vertebrate Paleontology 33 (5): 1138.  the name is something of a misnomer; adults possibly reached 3 m (10 ft) in length, and weighed .Montague, Jeremy R. 2006. Estimates of body size and geological time of origin for 612 dinosaur genera (Saurischia, Ornithischia). Florida Scientist, 69(4): 243-257. Mussaurus possesses anatomical features suggesting a close, possibly transitional evolutionary relationship with true sauropods.

 References 

category:Prosauropods