Austroraptor preying on fish, depicting a piscivore life-style
Most unenlagiines have been discovered in Argentina. The largest was Austroraptor, which measured up to 5–6 m (16.4–19.7 ft) in length, making it also one of the largest dromaeosaurids. The subfamily is distinguished from other dromaeosaurids by a tail stiffened by lengthy chevrons and superior processes, sharp articulate claws, and a posteriorly oriented pubis. Their distinct anatomy from Laurasian dromaeosaurids was likely a consequence of the breakup of Pangaea into Gondwana and Laurasia, where the geological isolation of unenlagiines from their relatives resulted in allopatric speciation.
During the description of Halszkaraptor in 2017, Cau et al. published a phylogenetic analysis of the Dromaeosauridae, in which, members of the Unenlagiinae are classified as:
^"Unenlagiinae". Paleobiology Database. Retrieved 31 July 2013.
^Orozco, José (December 17, 2008). ""Bizarre" New Dinosaur: Giant Raptor Found in Argentina". National Geographic News. Retrieved 2017-12-12.
GIANECHINI, FEDERICO A. (2011). "Unenlagiinae revisited: dromaeosaurid theropods from South America" (PDF). Anais da Academia Brasileira de Ciências (in English and Spanish). Ciudad Autónoma de Buenos Aires, Argentina: Brazilian Academy of Sciences. 83 (1): 163–195. doi:10.1590/s0001-37652011000100009. Retrieved 2017-12-12.
^Cau, A.; Beyrand, V.; Voeten, D.; Fernandez, V.; Tafforeau, P.; Stein, K.; Barsbold, R.; Tsogtbaatar, K.; Currie, P.; Godrfroit, P. (6 December 2017). "Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs". Nature. 552 (7685): 395–399. Bibcode:2017Natur.552..395C. doi:10.1038/nature24679. PMID29211712.