Strix is a genus of owls. They belong to the typical owl family (Strigidae), one of the two generally accepted living families of owls, with the other being the barn-owls (Tytonidae). Common names are earless owls or wood owls though they are not the only owls without ear tufts, and "wood owl" is also used as a more generic name for forest-living owls. Neotropical birds in the genus Ciccaba are sometimes included in Strix.
These are medium-sized to largish, robustly-built and powerful owls. They do not have ear tufts and most are highly nocturnal woodland birds. Most live on small mammals, birds and reptiles.
Note that although the genus Strix was established for the earless owls by Linnaeus in 1758, until the late 19th century many authors applied it to other owls – namely the Tytobarn-owls – in error.
The genus Strix is well represented in the fossil record. Being a fairly generic type of strigid owl, they were probably the first truly modern Strigidae to evolve. However, it is not certain whether several of the species usually placed in this genus indeed belong here.
Generally accepted in Strix are:
Strix dakota (Early Miocene of South Dakota, USA) – tentatively placed here
Strix sp. (Late Miocene of Nebraska, USA)
Strix sp. (Late Pliocene of Rębielice Królewski, Poland)
Strix intermedia (Early - Middle Pleistocene of EC Europe) – may be paleosubspecies of S. aluco
Strix brea (Late Pleistocene of SW North America)
Strix sp. (Late Pleistocene of Ladds, USA)
"Strix" wintershofensis (Early/Middle Miocene of Wintershof West, Germany) and "Strix" edwardsi (Middle Miocene of Grive-Saint-Alban, France), while being strigid owls, have not at present been reliably identified to genus; they might also belong into the European Ninox-like group.
"Strix" ignota (Middle Miocene of Sansan, France) is sometimes erroneously considered a nomen nudum but this assumption is based on what appears to be a lapsus or misprint in a 1912 source. It may well belong into the present genus, but this requires confirmation.
^Paris (1912: p.287) referred to Milne-Edwards (1869–1871: p.499) as the taxonomic authority, but the cited page only describes this owl but does not assign a specific name. However, the name Strix ignota is given on p.580 of Milne-Edwards's work referring unequivocally to the fossils described on page 499.