In 2018, Wang and colleagues described three new specimens similar to
Iteravis huchzermeyeri and
Gansus zheni, together comprising the only ornithurines described from the Sihedang locality of the Jiufotang Formation. Based on similarities between the three new specimens and the holotypes of the two named species, the authors concluded they all represented the same taxon, for which the species name
Iteravis huchzermeyeri has priority. Furthermore, their
phylogenetic analysis placed these in a single clade diverging before
Gansus yumenensis, the
type species of
Gansus. These results are displayed as
Topology A in an abbreviated
cladogram below. Shortly thereafter, Ju and colleagues (2021) independently published a more detailed comparison of
I. huchzermeyeri and
G. zheni. Similar to Wang et al. (2018), these authors concluded that the two species are synonymous. They further emphasized the distinction between
Iteravis and
Gansus (
G. yumenensis) at the genus level.
O'Connor and colleagues (2021) expressed that there are small differences observed between
I. huchzermeyeri and
G. zheni of "uncertain taxonomic significance". As such, they treated the two species as distinct, pending more thorough research. Regardless, their phylogenetic analyses placed these species as very close relatives (either in an unresolved
polytomy or as
sister taxa), distantly related to
G. yumenensis, reinforcing the generic distinction of the two
Gansus species. These results are displayed as
Topology B in an abbreviated cladogram below.
Topology A: Results of Wang et al. (2018)
Topology A: Results of Wang et al. (2025) |label1=}}
Topology B: Results of Huang et al. (2026) |3= }} }} }} == Palaeobiology ==