Strigogyps were formerly placed in part with the owls, specifically the Sophiornithidae; they appear to be Ameghinornithidae instead. For fossil species and paleosubspecies of extant taxa, see the genus and species articles. For a full list of extant and recently extinct owls, see the article List of owl species. Unresolved and basal forms (all fossil) Berruornis (Late Paleocene of France) basal? Sophornithidae? Strigiformes gen. et sp. indet. (Late Paleocene of Zhylga, Kazakhstan) Primoptynx (Early Eocene of Wyoming, U.S.) Palaeoglaux (Middle-Late Eocene of West-Central Europe) own family Palaeoglaucidae or Strigidae? Palaeobyas (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae? Palaeotyto (Late Eocene/Early Oligocene of Quercy, France) Tytonidae? Sophiornithidae? Strigiformes gen. et spp. indet. (Early Oligocene of Wyoming, U.S.) Ypresiglaux (Early Eocene of Essex, United Kingdom and Virginia, U.S.) Ogygoptyngidae Ogygoptynx (Middle/Late Paleocene of Colorado, U.S.) Protostrigidae Eostrix (Early Eocene of United States, Europe, and Mongolia). E. gulottai is the smallest known fossil (or living) owl. Minerva (Middle – Late Eocene of western U.S.) formerly Protostrix, includes "Aquila" ferox, "Aquila" lydekkeri, and "Bubo" leptosteus Oligostrix (mid-Oligocene of Saxony, Germany) Sophiornithidae Sophiornis Tytonidae Genus Tyto – the barn owls, grass owls, and masked owls, stand up to tall; some 15 extant species and possibly one recently extinct Genus Phodilus – the bay owls, two to three extant species and possibly one recently extinct Fossil genera Nocturnavis (Late Eocene/Early Oligocene) includes "Bubo" incertus Selenornis (Late Eocene/Early Oligocene) – includes "Asio" henrici Necrobyas (Late Eocene/Early Oligocene – Late Miocene) includes "Bubo" arvernensis and Paratyto Prosybris (Early Oligocene? – Early Miocene) Placement unresolved Tytonidae gen. et sp. indet. "TMT 164" (Middle Miocene) – Prosybris? Strigidae Genus Aegolius – the saw-whet owls, four species Genus Asio – the eared owls, eight species Genus Athene – two to four species (depending on whether the genera Speotyto and Heteroglaux are included or not) Genus Bubo – the horned owls, eagle-owls and fish-owls; paraphyletic with the genera Nyctea, Ketupa, and Scotopelia, some 25 species Genus Glaucidium – the pygmy owls, about 30–35 species Genus Gymnasio – the Puerto Rican owl Genus Gymnoglaux – the bare-legged owl or Cuban screech-owl Genus Lophostrix – the crested owl Genus Jubula – the maned owl Genus Megascops – the screech owls, some 20 species Genus Micrathene – the elf owl Genus Ninox – the Australasian hawk-owls or boobooks, some 20 species Genus Otus – the scops owls; probably paraphyletic, about 45 species Genus Pseudoscops