A long-snouted theropod
Buitreraptor gonzalezorum (Makovicky, Apesteguía & Agnolin, 2005, Fig. 1) was recovered as “a near-complete, small dromaeosaurid that is both the most complete and the earliest member of the Maniraptora from South America, and which provides new evidence for a unique Gondwanan lineage of Dromaeosauridae with an origin predating the separation between northern and southern landmasses.”
the large reptile tree nests Buitreraptor with the troodontid/pre-birds Aurornis and Anchiornis, two taxa published long after the publication of Buiteraptor. Wikipedia does not make this correction. I was unable to find any prior work linking these taxa.
Aurornis (Fig. 2) also has a large naris and maxillary fenestra, but not nearly as large. Aurornis is Late Jurassic. Buitreraptor is Cenomanian (earliest Late Cretaceous). So that evolutionary chronology makes sense.
Stem like coracoid
Unlike Aurornis, Buitreraptor had an elongated and waisted coracoid, so it is likely that Buitreraptor developped the habit of flapping by convergence with birds, parabirds and pseudo birds.
still nests with basal therizinosaurs.
Makovicky, PJ, Apesteguía S, Agnolín FL. 2005. The earliest dromaeosaurid theropod from South America. Nature 437: 1007–1011. Bibcode:2005Natur.437.1007M. doi:10.1038/nature03996. PMID 16222297.