[5] Eudromaeosauria itself was first defined as a node-based clade by Nick Longrich and Philip J. Currie in 2009, as the most inclusive natural group containing Dromaeosaurus, Velociraptor, Deinonychus, and Saurornitholestes, their most recent common ancestor and all of its other descendants.

A 2021 survey of the premaxillae, maxillae, nasals, lacrimals, and jugals of several eudromaeosaurs was conducted in an attempt to reconstruct the ancestral condition of facial pneumaticity for coelurosaurs.

The posterior caudal vertebrae, on the other hand, are marked by a loss of their transverse processes, a reduction in their neural spines, and the haemal arches take the shape of an upside-down 'T' in cross-section.

The skulls had few pneumatic spaces, especially in comparison to birds and oviraptorosaurs[22] and retained the slightly tapered rostrum of primitive tetanurans without any significant changes in length or depth.

[41] A 2024 paper studying eudromaeosaur skulls performed several analyses, including finite element analysis (FEA) in an attempt to infer their physical properties.

[45] The resting position of the elbow would likely have been an extremely acute angle for eudromaeosaurs, with the wings held close to the body, but not fully folded in the manner of modern birds.

[46] The mobility capabilities of eudromaeosaur arms were reconstructed in a 2006 analysis which used both direct observation of skeletal muscle correlates and phylogenetic inferences based on extant taxa.

Deinonychus is also believed to have exhibited considerable shoulder mobility due to the morphology of the scapular glenoid which, when coupled with the expanded muscle attachment sites near the wrists of these juveniles, may have enabled a mechanism approaching the "flapping" capabilities of birds.

The general morphology of the upper-body in juvenile Deinonychus, including the longer bones and the increased robustness in the shoulder girdle, also closely resembles the condition seen in other dromaeosaurids like Microraptor, Changyuraptor, and Sinornithosaurus, all of which have been suggested to be capable of powered flight.

This second toe bears the iconic sickle-shaped pedal claw that resembles the talons of birds of prey, from which many dromaeosaurs derive their names ("raptor" being a common generic suffix).

In 2005, a group of researchers led by Philip Manning constructed a robotic reconstruction of the leg of the eudromaeosaur Deinonychus in order to model possible functions for the hypertrophied second pedal claw.

Their tentative conclusion was that Deinonychus (and possibly other eudromaeosaurs) would have used their claws to climb onto the hides of large prey animals like Tenontosaurus in order to inflict wounds with their mouths.

[53] Peter Bishop performed an analysis of the foot musculature of Deinonychus in 2019 which sought to examine a wider variety of possible functional uses for their pedal claws.

A digital model of the leg of the animal was examined under several conditions to estimate the muscular optimization of different postures as a proxy for inferring potential in-life behaviors.

Bishop's analysis concluded that the leg musculature of Deinonychus — and by extension other eudroameosaurs — was most conducive to the use of their claws to hold-down smaller prey to kill or feed on them.

[55] Another analysis using a similar methodology with more taxa by Jonah Choiniere and colleagues was conducted in 2021 which examined scleral morphology of a wide range of pterosaurs, birds, and non-avian dinosaurs.

Among their sample were the taxa Tsaagan, Linheraptor, Dromaeosaurus, and Velociraptor, whose sensory capabilities were assessed using the morphology of their scleral rings and the endosseous cochlear ducts (ECDs) of their inner-ears.

[56] Archosaur cochlear shape elongated in a relatively linear fashion on the line towards birds, which was suggested by Michael Hanson and colleagues to be a paedomorphic adaptation to hear the high-pitched vocalizations of juveniles of the same species.

The oofossils were found in the Lianhe Formation near Ganzhou in southern China and were attributed to a droameosaur based on the microstructure of the eggshell and the similarities to the putative Deinonychus eggs listed above.

[10] The inner-ear morphology of Velociraptor and other eudromaeosaurs also suggests that they would have been able to discriminate very high-pitched sounds, which was possibly an adaptation for hearing the calls of their offspring in times of distress.

Based on examination of these specimens, it is known that juvenile Deinonychus differed from the adults of the same species by the presence of interdental plates, a relatively narrow mandible, and several features of the vertebrae.

[6] In 2012, Alan Turner, Mark Norell, and Peter Makovicky published a review of paravian systematics, which included a list of potential apomorphic characteristics for the group.

These include fully serrated teeth; vertically oriented pubis; pubic boot (or end) projecting anteriorly and posteriorly; the jugal process of the maxilla, in a ventral view to the external antorbital fenestra, is dorsoventrally wide.

[73] While several studies have since recovered a group of dromaeosaurids closely related to Velociraptor, they vary widely regarding which species are actually velociraptorines and which are either more basal or closer to Dromaeosaurus.

In 2005, Fernando Novas and Diego Pol found a distinct velociraptorine clade close to the traditional view, which included Velociraptor, Deinonychus, and material that was later named Tsaagan.

[35] The previous year, Hartman and colleagues recovered a similar clade including Deinonychus, Achillobator, Utahraptor, and Yixianosaurus, which was found to be more basal than any of the three traditional subfamilies.

[101] The similarly-aged Jydegaard Formation of Denmark has also yielded the tooth taxon Dromaeosauroides, which may have been a dromaeosaurine eudromaeosaur,[110] although some authors consider it to be dubious or an indeterminate dromaeosaurid.

The only eudromaeosaur genus from the Albian or Aptian (a roughly 20 million-year-long period) is Deinonychus, which is known from the Antlers, Cloverly, and Cedar Mountain formations throughout the western United States.

[68][21] Cenomanian and Turonian deposits have yielded several eudromaeosaurs of varying affinities including Achillobator, Itemirus, and a large unnamed taxon from the Bissekty Formation.

[62] A 2020 study by Alfio Alessandro Chiarenza and colleagues examined the fragmentary remains of a dromaeosaurid jaw from the Prince Creek Formation of Alaska and found this specimen (DMNH 21183) to be a member of Saurornitholestinae.