Sinosauropteryx
"Sinosauropteryx" was a small theropod with an unusually long tail and short arms. The longest known specimen reaches up to in length, with an estimated weight of It was a close relative of the similar but older genus "Compsognathus", both genera belonging to the family Compsognathidae. Only one species of "Sinosauropteryx" has been named: "S. prima", meaning "first" in reference to its status as the first feathered non-avialian dinosaur species discovered. Three specimens have been described. The third specimen previously assigned to this genus represents either a second, as-yet unnamed species or a distinct, related genus.
Dinosaur size
Size has been one of the most interesting aspects of dinosaur science to the general public and to scientists. Dinosaurs show some of the most extreme variations in size of any land animal group, ranging from the tiny hummingbirds, which can weigh as little as three grams, to the extinct titanosaurs, which could weigh as much as .