(An individual of Microspizias superciliosus, photographed by Aitor, under CC BY 4.0)

Meaning of name: Microspizias = small hawk

Species included: M. superciliosus (tiny hawk, type species, previously in Accipiter) and M. collaris (semicollared hawk, previously in Accipiter)

Age: Holocene (Meghalayan), extant

Where found: Forests of Central and South America

Notes: Microspizias is a genus of small (thrush-sized) hawks. Fairly little is known about the biology of the two living species, but they appear to prey mostly on other birds. They were formerly classified in the genus Accipiter, which includes a diverse assemblage of other forest-dwelling, bird-hunting hawks, such as the Eurasian sparrowhawk (A. nisus) and the sharp-shinned hawk (A. striatus). However, recent phylogenetic studies have found that the tiny hawk and semicollared hawk are not closely related to members of the genus Accipiter, instead being more closely related to the lizard buzzard (Kaupifalco monogrammicus).

Although some researchers have suggested that the old genus Hieraspiza could be brought back for the tiny hawk and the semicollared hawk on the basis that Gray (1955) designated the tiny hawk as its type species, the authors of a new paper argue that this designation is untenable because the first valid usage of the name Hieraspiza did not include the tiny hawk as a member of this genus. They thus coin the new genus Microspizias for these two species.