If Teviornis does belong to the Presbyornithidae then, together with Vegavis from Antarctica, there is evidence that relatives of today's waterfowl already were widespread and highly apomorphic by the end of the Mesozoic.

They concluded that some of the characters used by Kurochkin et al. to assign T. gobiensis to the Anseriformes, such as an unbowed metacarpal III, are plesiomorphies which are primitive for Avialae and also retained in some members of Ornithurae.

Moreover, Clarke and Norell found no synapomorphies of Aves (sensu Gauthier), Neognathae, or Galloanseres, preserved in PIN 4499–1, so they concluded that Teviornis cannot be confidently assigned to the Presbyornithidae.

Certain morphological traits of the type specimen including the facies articularis dimension and the craniocaudally elongated fossa are also found in the other presbyornithids such as Wilaru and Telmabates.

Other dinosaurs recovered from Gurillin Tsav include the tyrannosaurid Tarbosaurus, the ornithomimid Gallimimus, the oviraptorid Oksoko, the hadrosaurid Saurolophus, the pachycephalosaurid Prenocephale and the enantiornithine Gurilynia.