Named By: Novas - 1997.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, Theropoda, Deinonychosauria, Dromaeosauridae, Unenlagiinae.
Species: U. comahuensis, U. paynemili (Calvo et al - 2004).
Size: 2 meters long.
Known locations: Argentina.
Time period: Turonian to Coniacian of the Cretaceous.
Fossil representation: Twenty bones.
thought to be a juvenile Megaraptor,
was found to not only
be a separate species but one that would challenge the notions for the
origins of flight. Unenlagia fits into the
Unenlagiinae group, which
is also considered by some to be the rightful home of the dromaeosaur
If correct, that would mean that Unenlagia
either lost the
ability of flight after evolving from flying ancestors, or that
Rahonavis had evolved flight from others independent
from the accepted
Unenlagia is considered to be too large for flight itself, and the wings while having a high degree of motion, are thought to not being able to being raised above the spine. One consideration is that the wings were held out and used as stabilisers while chasing prey.
- New evidence concerning avian origins from the Late Cretaceous of Patagonia. - Nature 387:390-392. - F. E. Novas & P. F. Puerta - 1997.
- The earliest dromaeosaurid theropod from South America. - Nature 437 (7061): 1007–1011. - P J. Makovicky, S. Apesteguía & F. L Agnolin - 2005.
- Unenlagiinae revisited: dromaeosaurid theropods from South America. - Anais de Academia Brasileira de Ciencias 83(1): 163-195. - F.A. Gianechini & Sebastian Apesteguia - 2011.
- Unenlagiid theropods: are they members of the Dromaeosauridae (Theropoda, Maniraptora)? - Anais de Academia Brasileira de Ciências 83 (1): 117–162. - F. L. Agnolin & F. E. Novas - 2011.