Iteravis
Iteravis is an extinct genus of ornithuromorph bird known from the Early Cretaceous Jiufotang Formation of what is today the Liaoning Province of China. The genus contains a single species, Iteravis huchzermeyeri, named in honor of the archosaur palaeontologist Dr. Fritz Huchzermeyer, who died shortly before Iteravis was described. The relationships between Iteravis and species of Gansus have been debated, with some researchers arguing for a synonymy between the former and G. zheni, and others recovering a closer relationship between the two genera within the family Gansuidae.
Classification and taxonomy
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 independently published a more detailed comparison of I. huchzermeyeri and G. zheni. Similar to Wang et al., these authors concluded that the two species are synonymous. They further emphasized the distinction between Iteravis and Gansus at the genus level. O'Connor and colleagues 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, 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.
Topology B: Implied weighting results of O'Connor et al.
Wang et al., 2025 and Huang et al., 2026, both using phylogenetic matrices developed by Andrea Cau, recovered Iteravis as the sister taxon to Gansus yumenensis. The former analysis placed these taxa in a broader Gansuidae, also including Khinganornis, Shuilingornis, and Changzuiornis, while the latter analysis recovered Gansuidae as restricted to Iteravis and Gansus, diverging after a monophyletic clade comprising the aforementioned taxa. These results are displayed in the abbreviated cladograms below:
Topology A: Results of Wang et al.
Topology B: Results of Huang et al.