Microraptoria

Microraptoria (Greek, μίκρος, mīkros: "small"; Latin, raptor: "one who seizes") is a clade of basal dromaeosaurid theropod dinosaurs. Definitive microraptorians lived during the Barremian to Aptian stages of the Early Cretaceous in China. Probable microraptorian ichnotaxon Dromaeosauriformipes was discovered from the Jinju Formation of South Korea, and some fragmentary Late Cretaceous paravian fossils in North America have been described as putative members of this clade. Many are known for long feathers on their legs and may have been semiarboreal powered fliers, some of which were even capable of launching from the ground. Most microraptorians were relatively small; adult specimens of Microraptor range between ) and weigh up to , making them some of the smallest known non-avialan dinosaurs.

==Description== thumb|left|NGMC 91, believed to be a juvenile specimen of Sinornithosaurus|260x260px Microraptorians were a group of basal dromaeosaurids (popularly known as "raptors") with slender proportions and long limbs. All definitive members have been found in the Yixian and Jifuotang Formations of Liaoning County of China, so they're referred to as "Liaoning dromaeosaurids" by some researchers. These formations (collectively known as the Jehol Biota) have been dated to the early Cretaceous and at that time would have been part of a temperate wetland ecosystem threatened by frequent volcanic eruptions. Like other dromaeosaurids, microraptorians were carnivores with relatively large, serrated teeth and a hyperextendable second toe equipped with a curved claw. Some fragmentary paravian fossils from the Late Cretaceous (Campanian-Maastrichtian stages) of North America have been putatively suggested as microraptorians, though their taxonomic referral are considered controversial, namely Hesperonychus being recovered as an avialan in one phylogenetic analysis.