Open Paleo

Microraptor

Xu et al., 2000 MIE-kro-RAP-tor

From Greek 'mikros' (small) and Latin 'raptor' (one who seizes); meaning 'small thief' or 'small raptor'

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Microraptor is a genus of small, four-winged dromaeosaurid dinosaurs. Numerous well-preserved fossil specimens have been recovered from Liaoning, China. They date from the early Cretaceous Jiufotang Formation (Aptian stage), 125 to 120 million years ago. Three species have been named (M. zhaoianus, M. gui, and M. hanqingi), though further study has suggested that all of them represent variation in a single species, which is properly called M. zhaoianus. Cryptovolans, initially described as another four-winged dinosaur, is usually considered to be a synonym of Microraptor.

Diagnosis

  1. Anterior serrations absent on all teeth
  2. Posterior teeth have basal constriction between crown and root
  3. Middle caudal vertebrae about 3-4 times as long as anterior dorsal vertebrae
  4. Accessory crest of femur at the base of the lesser trochanter
  5. Tail with less than 26 vertebrae
  6. Strongly recurved and slender pedal unguals with prominent flexor tubercle

Species

Microraptor zhaoianus Xu et al., 2000

Type species

Named in honor of Zhao Xijin, a distinguished Chinese paleontologist who introduced the first author to the field of vertebrate paleontology.

Holotype
IVPP V12330 , Institute of Vertebrate Paleontology and Paleoanthropology
Material
A partial skeleton preserved in main and counter slabs.
Horizon
Jiufotang Formation, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Xiasanjiazi, Liaoning, China

Synonyms of the genus

Name Type Reason
Archaeoraptor nomen nudum Informal name; never met ICZN requirements for formal publication and is treated as referable to Microraptor. Per Olshevsky's Dinosaur Genera List.
Cryptovolans junior subjective Originally described as a separate four-winged dinosaur; subsequently recognized as referable to Microraptor.

Notable specimens

  • BMNHC PH881

    Beijing Museum of Natural History exceptional preservation

    Specimen whose fossilized melanosomes revealed probable glossy iridescent black plumage. It also showed a bifurcated tail fan with a pair of long narrow central feathers and no nuchal crest, indicating the crest inferred from the holotype was a taphonomic artifact.

    Li et al. (2012)

  • IVPP V17972

    Institute of Vertebrate Paleontology and Paleoanthropology gut contents

    Preserves the remains of an enantiornithine bird within its rib cage, direct evidence that Microraptor preyed on birds and likely foraged in the trees.

    O'Connor et al. (2011)

  • QM V1002

    Qijiang Dinosaur National Geological Park Museum gut contents

    Preserves fish scales in its abdominal cavity, evidence that Microraptor also hunted fish. Combined with anterodorsally inclined front teeth often associated with piscivory, it indicates Microraptor was an opportunistic feeder in both arboreal and aquatic habitats.

    Xing et al. (2013)

  • STM5-32

    Shandong Tianyu Museum of Nature gut contents

    Preserves a complete lizard, the new genus Indrasaurus, swallowed head-first in its stomach as in modern carnivorous birds and lizards. The lizard bones lack pitting and scarring, showing the Microraptor died shortly after eating, before significant digestion.

    Zhou et al. (2019)

References

  1. Xu, X.; Zhou, Z.; Wang, X. (2000). The smallest known non-avian theropod dinosaur. Nature 408(6813): 705-708. Springer Science and Business Media LLC. doi:10.1038/35047056 xu2000c
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026c
  3. Li, Q.; Gao, K. Q.; Meng, Q.; Clarke, J. A.; Shawkey, M. D.; D'Alba, L.; Pei, R.; Ellison, M.; Norell, M. A.; Vinther, J. (2012). Reconstruction of Microraptor and the evolution of iridescent plumage. Science 335(6073): 1215-1219. doi:10.1126/science.1213780 li2012a
  4. O'Connor, J.; Zhou, Z.; Xu, X. (2011). Additional specimen of Microraptor provides unique evidence of dinosaurs preying on birds. Proceedings of the National Academy of Sciences 108(49): 19662-19665. doi:10.1073/pnas.1117727108 o'connor2011a
  5. Xing, L.; Persons, W. S., IV; Bell, P. R.; Xu, X.; Zhang, J.; Miyashita, T.; Wang, F.; Currie, P. J. (2013). Piscivory in the feathered dinosaur Microraptor. Evolution 67(8): 2441-2445. doi:10.1111/evo.12119 xing2013b
  6. Zhou, Z.; Zhang, X.; Wang, Y.; Wang, X.; Dong, L.; Zheng, X.; O'Connor, J. (2019). Microraptor with ingested lizard suggests non-specialized digestive function. Current Biology 29(14): 2423-2429.e2. doi:10.1016/j.cub.2019.06.020 zhou2019a