Soroavisaurus

Soroavisaurus is a genus of enantiornithean birds related to Avisaurus. It lived during the Late Cretaceous of Argentina. The only known species, S. australis, is known from fossils collected from the Lecho Formation (Maastrichtian age) of Estancia El Brete, in the southern tip of the province of Salta, Argentina. A binominal name of this animal means "Southern sister Avisaur".

Description
The specimens are in the collection of the Fundación-Instituto Miguel Lillo, Tucumán. They are cataloged as PVL-4690, a 46.9 mm-long left tarsometatarsus, and PVL-4048, which includes another left tarsometatarsus, 51.5 mm-long and associated with the whole hallux, or digit I, and four intermediate phalanges. PVL-4048 was previously described as "Avisaurus sp." (see Avisaurus). PVL-4048, the largest undoubted individual of Soroavisaurus, indicates an animal with a length of 48.6 cm, hip height of 21.1 cm, and weight of 1.55 kg. PVL-4033, a tibiotarsus, probably belongs to a S. australis is also known, book published in 2019 estimated its length of 80 cm, hip height of 35 cm, and weight of 7.25 kg, making it the largest enantiornithean. However according to Walker and Dyke (2009) which considered PVL-4033 as Martinavis sp., its tibiotarsus length is 85.6 mm, much shorter than that of Lectavis (156 mm tibiotarsus) which the same book estimated a length of 41 cm, hip height of 30 cm, and weight of 1.15 kg.

Phylogeny
The cladogram below is from Wang et al., 2022:

Key to letters:

b = Boluochia c = Cathayornis e = Enantiophoenix f = Houornis h = Longipteryx i = Parabohaiornis j = Pterygornis l = Vorona m = Yuanjiawaornis n = Yungavolucris

Paleobiology
Due to their large size and strong talons, Soroavisaurus could occupy the same ecological niche as extanct birds of prey, noticing prey from afar on the plains or in water.