第一具遗骸于1980年在蒙大拿州发现,并非正式地称为“地狱溪组的阿瓦拉慈龙类”(Hell Creek alvarezsaur)。[5]此后,这一未命名物种没有被再次提到,直到2018年才在古脊椎动物学会(英语:Society of Vertebrate Paleontology)摘要书中简要提及。2020年,丹佛·福勒(Denver Fowler)及其同事根据MD-I-2的三个指骨(包括正模标本MOR 6622、桡骨远端和残缺的跖骨)对该属进行科学叙述。
^ 1.01.11.21.31.41.51.61.7Denver W. Fowler; John P. Wilson; Elizabeth A. Freedman Fowler; Christopher R. Noto; Daniel Anduza; John R. Horner. Trierarchuncus prairiensis gen. et sp. nov., the last alvarezsaurid: Hell Creek Formation (uppermost Maastrichtian), Montana. Cretaceous Research. 2020,. in press: Article 104560. doi:10.1016/j.cretres.2020.104560.
^ 2.02.1"Dinosaur distribution (Late Cretaceous; North America; Montana)." Weishampel, et al. (2004). Page 584.
^Fortey, Richard. Life: A natural history of the first four billion years of life on Earth. Vintage. 1999: 238–260. ISBN 978-0-375-70261-7.
^ 5.05.1Hutchinson and Chiappe, 1998. The first known alvarezsaurid (Theropoda: Aves) from North America. Journal of Vertebrate Paleontology. 18(3), 447–450.