The classification of the oviraptorids has been controversial. Most studies divide oviraptorosaurs into two primary sub-groups, the Caenagnathidae and the Oviraptoridae. However, some phylogenetic studies have suggested that many traditional members of the Caenagnathidae may more closely related to the crested oviraptorids. Because of this, and the fact that at least one study found that "Caenagnathus" itself may not have been part of the 'caenagnathid' group, Tom Holtz (2010) placed that group close to the Oviraptoridae and termed it the Elmisauridae, though this idea has not gained consensus among other researchers.