Belongs within: Icteridae.
Agelasticus is a South American genus of relatively slim blackbirds with a slender bill (Fraga 2011).
Agelasticus Cabanis 1851F11
|--A. thilius (Molina 1782)BKB15, F11 [=Turdus thiliusF11, Agelaius thiliusF11, Chrysomus thiliusF11]
| |--A. t. thiliusF11
| |--A. t. alticola (Todd 1932)F11
| `--A. t. petersii (Laubmann 1934)F11
`--+--A. cyanopus (Vieillot 1819)BKB15, F11 [=Agelaius cyanopusF11, Chrysomus cyanopusF11]
| |--A. c. cyanopusF11
| |--A. c. atroolivaceus (Wied 1831)F11
| |--A. c. beniensis (Parkes 1966)F11
| `--A. c. xenicus (Parkes 1966)F11
`--A. xanthophthalmus (Short 1969)BKB15, F11 [=Agelaius xanthophthalmusF11, Chrysomus xanthophthalmusF11]
*Type species of generic name indicated
References
[BKB15] Burleigh, J. G., R. T. Kimball & E. L. Braun. 2015. Building the avian tree of life using a large-scale, sparse supermatrix. Molecular Phylogenetics and Evolution 84: 53–63.
[F11] Fraga, R. M. 2011. Family Icteridae (New World blackbirds). In: Hoyo, J. del, A. Elliott & D. A. Christie (eds) Handbook of the Birds of the World vol. 16. Tanagers to New World Blackbirds pp. 684–807. Lynx Edicions: Barcelona.