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.
Sillosuchus
However, other remains indicate that it could grow much larger. Most notable among additional remains was PVL 2267, an isolated cervical (neck vertebra) initially misidentified as belonging to the giant quadrupedal predator "Saurosuchus," a distant relative of "Sillosuchus". This bone was 20 centimeters (8 inches) long, while cervicals from the holotype were only 8 centimeters (3 inches) long. Using its more complete relatives to estimate length, this bone likely belonged to a "Sillosuchus" that was 9-10 meters (30-33 feet) in length. This would indicate that "Sillosuchus" was among the largest terrestrial pseudosuchians (crocodilian-line archosaurs).