Alvarezsauroidea

Achillesaurus is a genus of alvarezsaurid theropod dinosaur from the Santonian-aged (Late Cretaceous) Bajo de la Carpa Formation of Rio Negro, Argentina. It contains one species, Achillesaurus manazzonei.

Alvarezsauroidea (from the Argentine historian, writer and physician Gregorio Álvarez) is a group of small maniraptoran dinosaurs. The group was first formally proposed by Choiniere and colleagues in 2010, to contain the family Alvarezsauridae and non-alvarezsaurid alvarezsauroids, such as Haplocheirus, which is the basalmost of the Alvarezsauroidea (from the Late Jurassic, Asia). The discovery of Haplocheirus extended the stratigraphic evidence for the group Alvarezsauroidea about 63 million years further in the past. The division of Alvarezsauroidea into the Alvarezsauridae and the non-alvar

Xixianykus is a genus of alvarezsaurid theropod dinosaur known from a slab of rock which contains a partial postcranial skeleton unearthed in the Late Cretaceous (Coniacian-Santonian) Majiacun Formation of the Xixia Basin in Henan, China.

Bannykus is an extinct genus of alvarezsauroid from the Early Cretaceous Bayin-Gobi Formation of Inner Mongolia, China. It includes one species, Bannykus wulatensis.

Alnashetri is an extinct genus of alvarezsauroid coelurosaurian theropod dinosaur known from the early Late Cretaceous (Cenomanian stage) of La Buitrera, Río Negro Province, Argentina. It contains one known species, Alnashetri cerropoliciensis. Its remains were discovered in Candeleros Formation.

Tugulusaurus (meaning "Tugulu lizard") is a genus of coelurosaurian theropod dinosaur, belonging to the Alvarezsauroidea, that is known from the Early Cretaceous Tugulu Group in the Urhe area of China. It was one of the first members of Alvarezsauria ever discovered. The type and only known species is T. faciles.

Xiyunykus (meaning "western claw"; "xiyu" is Mandarin for "west" and refers to Western China where it was found) is a genus of alvarezsauroid theropod from the Early Cretaceous-aged Tugulu Group of what is now China. Only one species has been described, Xiyunykus pengi.

Shishugounykus (meaning "Shishugou claw") is a genus of basal alvarezsaurian dinosaur from the Shishugou Formation of Xinjiang, China. The type and only species is Shishugounykus inexpectus. The specific name refers to the unexpected discovery of another species of alvarezsaur from the Shishugou Formation (other alvarezsaurs from this formation include Haplocheirus and possibly Aorun). Its affinities to alvarezsaurs have subsequently been questioned.