"Gigantoraptor" belonged to the Oviraptorosauria, a group named after "Oviraptor". Compared to other known members, "Gigantoraptor" was much larger, about three times as long and 35 times more massive than the earlier discovered oviraptorosaurid "Citipati". Xu "et al." estimated the length at and the weight at 1400 kilogrammes. In 2010 Gregory S. Paul even gave an estimate of two tonnes (2.2 tons).