[4] Deinonychosauria is commonly defined as all dinosaurs more closely related to dromaeosaurids (such as Deinonychus antirrhopus) than to birds (such as Passer domesticus).

[7] The unit was not much referred to, and when Hans Friedrich Gadow in 1893 erected Archaeornithes for basically the same fossils, this became the common name for the early reptile-like grade of birds.

[8] According to Romer, the Archaeornithes are characterised by having clawed wings, a reptilian style ribcage without a large carina and the presence of a long, bony tail.

[14]The name Deinonychosauria was coined by Ned Colbert and Dale Russell in 1969, and defined as a clade (all theropods closer to dromaeosaurids than to birds) by Jacques Gauthier in 1986.

[15] In 2012, Turner et al. conducted a phylogenetic analysis (using a dataset of 474 characters scored for 111 taxa) which found Deinonychosauria to be monophyletic.

[16] With the description in 2019 of the Late Jurassic genus Hesperornithoides, Hartman et al., using every named Mesozoic maniraptoromorph (with the addition of 28 unnamed specimens), which they scored 700 characters and 501 operational taxonomic units, found that most of the anchiornithids are members of Archaeopterygidae, Halszkaraptorinae and Unenlagiinae are in a redefined family Unenlagiidae, and a Dromaeosauridae sensu stricto is the sister taxon of Troodontidae.

[1] The authors opted for Deinonychosauria (defined as dinosaurs closer to Deinonychus antirrhopus than to Passer domesticus) over "Archaeopterygiformes".

[1] Archaeopterygidae (including Anchiornithidae) Unenlagiidae (Halszkaraptorinae + Unenlagiinae) Dromaeosauridae (Microraptoria + Eudromaeosauria) Troodontidae In a study conducted in 2020, Archaeopteryx was recovered as an avialan.

While this characteristic claw and its associated modifications to the anatomy of the foot (such as a shortened metatarsus in eudromaeosaurs) had been known since the mid-20th century, their possible functions were the subject mainly of speculation, and few actual studies were published.

In this scenario, the shortened upper foot would serve as an anchor point for powerful tendons to improve kicking ability.

This makes it likely that advanced dromaeosaurids also used their claws to puncture and grip their prey to aid in pinning it to the ground, while using shallow wing beats and tail movements to stabilize themselves.