Senter et al. 2004 erected this taxon to encompass a clade consisting of Microraptor, Sinornithosaurus, and Bambiraptor. In their analysis, this clade was found to be the sister taxon of Dromaeosauridae, which consisted of most “traditional” dromaeosaurids (e.g. Dromaeosaurus, Velociraptor, Deinonychus). The reason Senter et al. (2004) erected this taxon, rather than one of familial or subfamilial form, was because they were concerned about its inclusion within other taxa of equivalent rank. These concerns, however, are easily handled in a definition by external specifiers. Microraptorinae is defined elsewhere in this compilation as an active taxon.