Name: Unenlagia
(Half
bird).
Phonetic: U-nen-lag-ee-ah.
Named By: Novas - 1997.
Classification: Chordata, Reptilia, Dinosauria,
Saurischia, Theropoda, Deinonychosauria, Dromaeosauridae, Unenlagiinae.
Species: U. comahuensis, U. paynemili.
Type: Carnivore.
Size: Estimated between 2 and 3.5 meters long.
Known locations: Argentina.
Time period: Turonian to Coniacian of the Cretaceous.
Fossil representation: Twenty bones.
Initially
thought to be a juvenile Megaraptor,
Unenlagia
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
Rahonavis.
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
Archaeopteryx lineage.
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.
Further reading
- 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. Apestegu�a & 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 Ci�ncias 83
(1): 117–162. - F. L. Agnolin & F. E. Novas - 2011.