Open Paleo

Rahonavis

Forster et al., 1998 rah-HOON-a-vis

From Malagasy 'rahona' meaning 'cloud' or 'menace' and Latin 'avis' meaning 'bird', named for its bird-like nature and discovery in Madagascar.

72.2–66.0 million years ago Maastrichtian, Late Cretaceous
Late Cretaceous stages

Rahonavis is a genus of bird-like theropod from the Late Cretaceous (Maastrichtian, from about 70 to 66 mya) of what is now northwestern Madagascar. It is known from a partial skeleton (UA 8656) found by Catherine Forster and colleagues in Maevarano Formation rocks at a quarry near Berivotra, Mahajanga Province. Rahonavis was a small predator, at about 70 centimeters (2.3 ft) long and 0.45-2.27 kg (1-5 lbs), with the typical dromaeosaurid-like raised sickle claw on the second toe. It was the first coelurosaur discovered in Africa, with Nqwebasaurus being the second.

Under dispute

Rahonavis has an unusually contested position even among unenlagiines. It was originally described as a bird more derived than Archaeopteryx (Forster and colleagues, 1998), and several analyses continue to recover it on the avialan stem (Agnolín and Novas, 2013; Cau, 2018; as the Overoraptor + Rahonavis clade sister to Avialae in Motta and colleagues, 2020). Other analyses recover it as a dromaeosaurid unenlagiine (Makovicky and colleagues, 2005; Turner and colleagues, 2012; Hartman and colleagues, 2019, the last requiring ten extra steps to make it avialan). Because the unenlagiine (dromaeosaurid) and stem-avialan hypotheses straddle the Dromaeosauridae-Avialae split, Paraves is the least-inclusive clade both accept.

Diagnosis

  1. Robust, hyperextendible second pedal digit terminating in sickle-like claw
  2. Hyposphene-hypantra articulations on dorsal vertebrae retained
  3. Six fused sacral vertebrae
  4. Reversed hallux characteristic of birds
  5. Elongate ulna with six quill knobs for secondary flight feathers
  6. Vertical pubis with well-developed hypopubic cup
  7. Greatly reduced fibula lacking contact with calcaneum

Species

Rahonavis ostromi Forster et al., 1998

Type species

Named for John Ostrom, the American paleontologist renowned for work on dromaeosaurids and the theropod origin of birds.

Holotype
UA 8656 , Universite d’Antananarivo
Material
Partial skeleton
Horizon
Maevarano Formation, Maastrichtian, Late Cretaceous , 72.2–66.0 million years ago
Locality
MAD 93-18, Mahajanga, Madagascar

Synonyms of the genus

Name Type Reason
Rahona preoccupied Name preoccupied by Rahona (Lepidoptera).

References

  1. Forster, C. A.; Sampson, S. D.; Chiappe, L. M.; Krause, D. W. (1998). The Theropod Ancestry of Birds: New Evidence from the Late Cretaceous of Madagascar. Science 279(5358): 1915-1919. American Association for the Advancement of Science (AAAS). doi:10.1126/science.279.5358.1915 forster1998a
  2. Forster, C. A.; Sampson, S. D.; Chiappe, L. M.; Krause, D. W. (1998). Genus Correction. Science 280(5361): 179-179. American Association for the Advancement of Science (AAAS). doi:10.1126/science.280.5361.179g forster1998b
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

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

    jones2026c
  4. Cau, A. (2018). The assembly of the avian body plan: a 160-million-year long process. Bollettino della Società Paleontologica Italiana 57(1): 1-25. doi:10.4435/BSPI.2018.01

    Recovered Rahonavis on the avialan stem.

    cau2018a
  5. Motta, M. J.; Agnolín, F. L.; Brissón Egli, F.; Novas, F. E. (2020). New theropod dinosaur from the Upper Cretaceous of Patagonia sheds light on the paravian radiation in Gondwana. The Science of Nature 107(3). Springer Science and Business Media LLC. doi:10.1007/s00114-020-01682-1

    Recovered an Overoraptor+Rahonavis clade as sister to Avialae on the avialan stem.

    motta2020a
  6. Makovicky, P. J.; Apesteguía, S.; Agnolín, F. L. (2005). The earliest dromaeosaurid theropod from South America. Nature 437(7061): 1007-1011. Springer Science and Business Media LLC. doi:10.1038/nature03996

    Recovered Rahonavis as a dromaeosaurid unenlagiine in their phylogenetic analysis.

    makovicky2005a
  7. Turner, A. H.; Makovicky, P. J.; Norell, M. A. (2012). A Review of Dromaeosaurid Systematics and Paravian Phylogeny. Bulletin of the American Museum of Natural History 371: 1-206. doi:10.1206/748.1

    Review of dromaeosaurid systematics recovered Rahonavis nested within Unenlagiinae.

    turner2012a
  8. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247

    New paravian analysis required extra steps to recover Rahonavis as avialan, favoring dromaeosaurid placement.

    hartman2019a
  9. Agnolín, F. L.; Novas, F. E. (2013). Avian Ancestors. SpringerBriefs in Earth System Sciences. Springer Netherlands. doi:10.1007/978-94-007-5637-3

    Recovered Rahonavis on the avialan stem.

    agnolín2013a