Flying Dinosaurs: Microraptor, Norellraptor, and the Evolution of Flight

Birds are dinosaurs, but they were not the only dinosaurs to experiment with the air. Several close relatives of birds evolved wings, feathers, gliding, or possible powered flight in different ways. This article looks at the strange non-avian dinosaurs that show flight was not a simple one-time leap from ground-running dinosaur to modern bird.

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Introduction: Dinosaurs Took to the Air in More Than One Way

Birds are dinosaurs, specifically living avian theropods. But the evolution of flight among dinosaurs was not a neat, single-file march toward modern birds. The fossil record now shows a much messier and more interesting story. Several small theropod dinosaurs close to the origin of birds evolved feathers, long wings, aerodynamic tails, and climbing adaptations.

Some of these animals may have glided. Others may have been capable of powered flight. Some were evolutionary dead ends. Together, they show that flight-related anatomy appeared repeatedly among paravian dinosaurs, especially near the bird-dromaeosaur part of the dinosaur family tree.

Pterosaurs Are Not Dinosaurs

First, it is worth clearing up a common point of confusion: pterosaurs were not dinosaurs. Pterosaurs were flying reptiles and close relatives of dinosaurs within Archosauria, but they were outside Dinosauria. They evolved powered flight independently, long before birds appeared. To learn more about them, see the Fossilguy pterosaur guide.

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Bird Evolution Overview

Birds evolved from small feathered theropod dinosaurs. They are part of the broader paravian radiation, the same general evolutionary neighborhood that includes dromaeosaurs, troodontids, and other close bird relatives. By the Late Jurassic, birds such as Archaeopteryx already show a mix of birdlike and theropod traits: feathers, wings, teeth, a long bony tail, clawed fingers, and a body plan still close to non-avian dinosaurs.

Archaeopteryx

Archaeopteryx is one of the most famous early birds. It lived about 150 million years ago in what is now Germany. It could probably fly or at least perform some form of wing-assisted aerial movement, but it was not built like a modern bird. It retained teeth, a long tail, fingers with claws, and other theropod traits. Its importance is that it shows birds were already distinct by the Late Jurassic, meaning the origin of birds must be older than Archaeopteryx itself.

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Dinosaurs That Were Experimenting with Flight

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Dromaeosaurids and Microraptorines: The Four-Winged Dinosaurs

Dromaeosaurids are the raptor dinosaurs. They were close relatives of birds and shared many traits with them, including feathers, hollow bones, a wishbone, nesting behavior, and in some cases long wing feathers. Some dromaeosaurs remained ground-based predators, but several small species evolved aerodynamic structures that suggest climbing, gliding, or possibly powered flight.

Microraptorines are especially important because they include small, feathered dromaeosaurs with long flight feathers on both the arms and legs. These four-winged dinosaurs are unlike anything alive today. Their anatomy suggests that early dinosaur flight may have included climbing, leaping, gliding, wing-assisted movement, and short bursts of powered flight.

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Norellraptor barsboldi: A New Microraptorine and a Big Clue About Flight

Norellraptor barsboldi was described from an exceptionally preserved feathered microraptorine fossil from the Lower Cretaceous Jiufotang Formation in Liaoning, China. Its discovery is important because it gives researchers another well-preserved example of a winged, bird-like dinosaur outside the direct bird lineage.

The key point is not simply that Norellraptor had feathers or wings. The important part is what it suggests about how the flight apparatus evolved. The 2026 study argued that microraptorines assembled their flight-related anatomy differently from the avian lineage. In other words, non-avian flying dinosaurs were not just copying the same developmental path that led to birds. They were running a separate evolutionary experiment with wings, feathers, limbs, growth patterns, and aerial ability.

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Microraptor gui

Microraptor gui is probably the most famous non-avian flying dinosaur. It had long feathers on its arms, legs, and tail, creating a four-winged body plan. Studies of its feathers and body shape suggest it was capable of some form of aerial movement, although it probably did not fly with the grace or efficiency of modern birds.

The exact posture of Microraptor has been debated. Early ideas included a sprawled “X-wing” posture, but later aerodynamic modeling suggested other arrangements, including a tent-like configuration in which the hind wings were held closer to the tail. Its lifestyle was likely tied to trees, but stomach contents from different individuals include a small mammal, bird, lizard, and fish, suggesting it used a wide range of habitats or feeding opportunities.

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Rahonavis: Bird or Dromaeosaur?

Rahonavis ostromi is a small Late Cretaceous paravian from Madagascar. It is important because it sits close to the blurry boundary between early birds and non-avian dromaeosaurs. Some studies place it closer to birds, while others place it within Dromaeosauridae or near unenlagiine dromaeosaurs.

Rahonavis had quill knobs on the ulna, indicating strong feather attachment. Its arms appear to have been powerful compared with many other early paravians, and aerodynamic studies have suggested it may have had powered flight potential. Even if its exact family position remains debated, Rahonavis shows how difficult it can be to draw a clean line between early birds and their closest non-avian relatives.

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The Bat-Wing Dinosaurs: Jurassic Scansoriopterygids

Not all dinosaur flight experiments used birdlike feathers. Scansoriopterygids were small Jurassic dinosaurs from China that evolved a completely different kind of wing. Instead of relying on long flight feathers, they had a membranous wing supported by an elongated finger and a rod-like wrist bone. This gave them a bat-like appearance, although they were dinosaurs, not bats, birds, or pterosaurs.

The best-known example is Yi qi. Aerodynamic work suggests these dinosaurs were probably poor gliders rather than strong powered fliers. Their anatomy looks like an evolutionary experiment that did not lead to a long-lasting flying lineage, but it is still one of the most remarkable examples of how many different ways dinosaurs experimented with moving through the air.

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What This Means for Dinosaur Flight

Group	Wing Type	Likely Aerial Ability	Why It Matters
Birds	Feathered forelimb wings	Powered flight	The only dinosaur flight lineage that survived the end-Cretaceous extinction.
Microraptorines	Feathered arms, legs, and tail	Gliding to possible powered flight	Shows a separate paravian experiment with four-winged aerial movement.
Rahonavis	Feathered forelimbs	Possible powered flight	Blurs the boundary between birds and close non-avian relatives.
Scansoriopterygids	Membrane wings	Likely gliding	Shows a bat-like dinosaur wing experiment unrelated to bird-style flight.

When you think of flying dinosaurs, do not think only of modern birds. Birds are the surviving branch, but the fossil record shows a wider story. Some dinosaurs had four wings. Some had membrane wings. Some had flight-related anatomy that developed differently from birds. Most of these experiments ended, but together they show that the air was an evolutionary frontier dinosaurs explored more than once.

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Flying Dinosaur FAQ

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Recommended Dinosaur Books and Educational Items:

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High quality dinosaur teeth by Fossilera

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References / Works Cited

Agnolín, F.L. and Novas, F.E. (2013) Avian Ancestors: A Review of the Phylogenetic Relationships of the Theropods Unenlagiidae, Microraptoria, Anchiornis and Scansoriopterygidae. SpringerBriefs in Earth System Sciences.

Cau, A., Ji, Q., Wang, X., et al. (2026) Independent assembly of the flight apparatus in a non-avian dinosaur clade. Nature Communications. Article here.

Dececchi, T.A.; Roy, A.; Pittman, M.; Kaye, T.G.; Xu, X.; Habib, M.B.; Larsson, H.C.E.; Wang, X.; Zheng, X. (2020) Aerodynamics show membrane-winged theropods were a poor gliding dead-end. iScience, 23(12), 101574. DOI: 10.1016/j.isci.2020.101574

Evangelista, D. et al. (2014) Aerodynamic characteristics of a feathered dinosaur measured using physical models: effects of form on static stability and control effectiveness. PLoS ONE 9(1):e85203. DOI: 10.1371/journal.pone.0085203

Forster, O'Connor, Chiappe and Turner (2020) The osteology of the Late Cretaceous paravian Rahonavis ostromi from Madagascar. Palaeontologia Electronica 23(2):a31. DOI: 10.26879/793

Hone, D.W.E.; Tischlinger, H.; Xu, X.; Zhang, F.M. (2010) The extent of the preserved feathers on the four-winged dinosaur Microraptor gui under ultraviolet light. PLoS ONE 5(2):e9223. DOI: 10.1371/journal.pone.0009223

Pei, R.; Pittman, M.; Goloboff, P.A.; Dececchi, T.A.; Habib, M.B.; Kaye, T.G.; Larsson, H.C.E.; Norell, M.A.; Brusatte, S.L.; Xu, X. (2020) Powered flight potential approached by wide range of close avian relatives but achieved selectively. DOI: 10.1101/2020.04.17.046169

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