Sinosauropteryx
"Sinosauropteryx" was a small bipedal theropod, noted for its short arms, large first finger (thumbs), and long tail. The taxon includes some of the smallest known adult non-avian theropod specimens, with the holotype specimen measuring only in length, including the tail. However, this individual was relatively young. The longest known specimen reaches up to in length, with an estimated weight of .
Sauropoda
Among the smallest sauropods were the primitive "Ohmdenosaurus" (4 m, or 13 ft long), the dwarf titanosaur "Magyarosaurus" (6 m or 20 ft long), and the dwarf brachiosaurid "Europasaurus", which was 6.2 meters long as a fully-grown adult. Its small stature was probably the result of insular dwarfism occurring in a population of sauropods isolated on an island of the late Jurassic in what is now the Langenberg area of northern Germany. The diplodocoid sauropod "Brachytrachelopan" was the shortest member of its group because of its unusually short neck. Unlike other sauropods, whose necks could grow to up to four times the length of their backs, the neck of "Brachytrachelopan" was shorter than its backbone.