Small size,[4] a terrestrial lifestyle,[5] and a generalist diet[6] have all been inferred as ecological advantages possessed by early neornithes, allowing them to survive and diversify in the wake of the extinction.

This was supported by biogeographic ancestral reconstructions using phylogenies[8] and the discovery of Vegavis (a possible neornithean from Antarctica),[9] but Asteriornis's presence in Europe suggests that modern birds may have been widespread in northern continents in their early evolution.

It was retrieved from four blocks of sediment found at the CBR-Romontbos quarry near Eben-Emael in the Maastricht Formation of Belgium,[1] and was first unearthed in 2000,[10] by amateur paleontologist Maarten van Dinther,[11] who donated it to the museum.

Leg bones are elongated and slender, similar in proportions and structure to modern ground-living birds.

[1] A phylogenetic analysis placed Asteriornis near the base of Galloanserae, an expansive superorder containing birds such as chickens, ducks, pheasants, and other types of fowl and gamebirds.

Parsimony placed it as the sister taxon to Galloanserae, meaning that it was a distant relative of the last common ancestor of chickens and ducks.

One of the oldest known neognath, specifically a stem-anseriform, is the presbyornithid Teviornis from the Nemegt Formation of Mongolia around 70 million years ago.

[16] Asteriornis is based on diagnostic and well-preserved skull material and its status is less unstable, so it can be considered among the oldest known undisputed fossil of a modern-style neornithean bird.

[17][18] Other researchers still support Asterornis as a neornithean closely related to or within Galloanserae based on morphometric and phylogenetic analyses.

[19][20] A cladistic analysis from a 2024 in-press article placed Asteriornis within the crown-group Galloanserae, specifically as a stem-galliform, though reexaminations of its mandible suggested that it lacked a key galloanserine feature.