In addition to further complicating diversity of Liaoning dromaeosaurids, this specimen provides the first direct evidence of well-developed pennaceous feathers in a large, non-flying dromaeosaur, raising the question of what function such wings would serve.

In 2015, the type species Zhenyuanlong suni was named and described by paleontologists Lü Junchang of the Chinese Academy of Geological Sciences in Beijing and Stephen Brusatte of the University of Edinburgh in the United Kingdom.

[3] The holotype, JPM-0008, was found in the Sihedang locality of Jianchang County of northeastern China's Yixian Formation, which dates from the Aptian age of the Early Cretaceous (125–113 million years ago).

[2] The type fossil of Zhenyuanlong preserves integument on several parts of the specimen, including a "hairy" coat of simple filaments over most of the body and large, vaned feathers on the tail and arms, which would have given the animal a life appearance indistinguishable from a bird.

Whether the animal's body feathers were simple and non-shafted or more complex filaments attaching to a central vane is impossible to determine from this specimen.

The wings were broad, with a total surface area of about one square meter each, but their precise shape is unknown due to taphonomic distortion.

[2] At around 2 metres in length and covered in complex feathers, Zhenyuanlong would have been virtually indistinguishable from a large bird in life, and has been compared to a turkey, emu, or "big chicken", with wings similar to those of an eagle or vulture.

[6] Zhenyuanlong is considered by its authors to be a "rare and aberrant animal" compared to the related group of Liaoning dromaeosaurids to which it belongs, due to its large body size and short arms.

[7] Though the authors state that the animal is likely too big to fly,[4] they also stress the importance of biomechanical modeling before drawing specific conclusions about the aerodynamic function (or lack thereof) of Zhenyuanlong's wings.

One possibility is that Zhenyuanlong is secondarily flightless, having a shared ancestry with smaller, potentially volant dromaeosaurids like Microraptor and then retaining aspects of flight capability through inertia or unknown adaptive reasons.

[2] Other possibilities include the use of wings in displaying to mates or rivals, protecting eggs in its nest, or even some amount of arboreal gliding.

[1] According to the authors and other paleontologists, the most viable hypothesis at this time is the use of the wings in sexual display, either to threaten rivals or to court potential mates, much as a peacock uses its tail to impress hens.

The authors' cladistic analysis recovered it in the same position in the evolutionary tree as the other five Liaoning dromaeosaurids (Changyuraptor, Graciliraptor, Microraptor, Sinornithosaurus, and Tianyuraptor) and the Eudromaeosauria though their exact relationships could not be resolved.

[2] Mahakala Unenlagia Austroraptor Buitreraptor Rahonavis Graciliraptor Changyuraptor Microraptor Sinornithosaurus Tianyuraptor Zhenyuanlong Bambiraptor Saurornitholestes Tsaagan Adasaurus Deinonychus Balaur Velociraptor Achillobator Utahraptor Atrociraptor Dromaeosaurus It was noted that Zhenyuanlong did not necessarily form its own group or clade with Tianyuraptor, despite uniquely sharing short arms among the Liaoning dromaeosaurids, and nor did the Liaoning dromaeosaurids form their own clade.

This condition, where a node (which represents a shared ancestor) begets multiple immediate branches that don't cluster into further groups, is known as a polytomy and reflects phylogenetic uncertainty.