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.
Sinomastodon
The animal was very similar to modern elephants with size ranging from 3.6 to 5.3 m. Several species are known from China, the best known being "S. hanjiangensis" from the Late Miocene and Early Pliocene of the Shanxi province. It is known from an incomplete skeleton of an adult (measuring 5.3 m) including maxilla, mandibles, teeth, tusks and other materials have been discovered. The Japanese species "S. sendaicus" described in 1924 from dentary materials from Pliocene deposits has been ascribed to the genus, as well as the species "S. bumiajuensis" (formerly "Tetralophodon") from the late Pliocene of Java. One individual of "S. hanjiangensis" was a 30-year-old tall and weighed .