Fossil poaching has become a serious problem in Mongolia in the 21st century, and several "Gallimimus" specimens have been looted. In 2017, Hang-Jae Lee and colleagues reported a fossil trackway discovered in 2009 associated with a clenched "Gallimimus" foot (specimen MPC-D100F/17). The rest of the skeleton appeared to have been removed previously by poachers, along with several other "Gallimimus" specimens (as indicated by empty excavation pits, garbage, and scattered broken bones in the quarry). It is unusual to find tracks closely associated with body fossils; some of the tracks are consistent with ornithoimimid feet, while others belong to different dinosaurs. In 2014, a slab with two "Gallimimus" specimens was repatriated to Mongolia along with other dinosaur skeletons, after having been smuggled to the US. In 1988, the palaeontologist Gregory S. Paul concluded that the skulls of ornithomimids were more similar to each other than previously thought and moved most species into the same genus, "Ornithomimus", resulting in the new combination "O. bullatus". In 2010, he instead listed it as ""Gallimimus" (or "Struthiomimus") "bullatus"", but returned to using only the genus name "Gallimimus" in 2016. The species involved have generally been kept in separate genera by other writers. An ornithomimid vertebra from Japan informally named "Sanchusaurus" was reported in a 1988 magazine, but was assigned to "Gallimimus" sp. (of uncertain species) by the palaeontologist Dong Zhiming and colleagues in 1990. Barsbold informally referred to a nearly complete skeleton (IGM 100/14) as "Gallimimus mongoliensis", but since it differs from "Gallimimus" in some details, Yoshitsugu Kobayashi and Barsbold proposed in 2006 that it probably belongs to a different genus. In 2000, the palaeontologist Philip J. Currie proposed that "Anserimimus", which is only known from one skeleton from Mongolia, was a junior synonym of "Gallimimus", but this was dismissed by Kobayashi and Barsbold, who pointed out several differences between the two. Barsbold noted some morphological variation among newer "Gallimimus" specimens, though this has never been published. "Gallimimus" is the largest known member of the family Ornithomimidae.