Mussaurus

Mussaurus patagonicus was a large herbivorous prosauropod that lived in Argentine 215 million years ago during the Late Triassic period. First specimens were discovered in 1979 by José F. Bonaparte and Martin Vince. Mussaurus means 'Mouse Lizard'. All specimens which have been discovered are of infants, complete with egg scales. Adults possibly reached 3 m (10 ft) in length, and weighed 70 kilograms (150 lb).

The Lost World (novel)
Mussaurus is the first living dinosaur Richard Levine sees on Isla Sorna. In honour to the available data this Mussaurus is an infant.