Falco peregrinus (Turnstall 1771) is the extant peregrine falcon, a smaller version of Sagittarius with shorter legs and high speed wings (380+kmh/240+mph). Eagles and owls are very similar to this taxon.

Didunculus strigirostris (Jardine 1845; Peale 1848; 31cm in length) is the rare, but extant tooth-billed pigeon. In the LRT this parrot-like bird does not nest with pigeons, but with Falco the falcon.

Messelastur gratulator (Peters 1994, middle Eocene) was considered a link between falcons and owls, but here nests with Didunculus.

Mayr G 2005. The postcranial osteology and phylogenetic position of the Middle Eocene Messelastur gratulator Peters, 1994—a morphological link between owls (Strigiformes) and falconiform birds? Journal of Vertebrate Paleontology 25(3):635–645.

Mayr G 2011. Well-preserved new skeleton of the Middle Eocene Messelastur substantiates sister group relationship between Messelasturidae and Halcyornithidae (Aves, ? Pan-Psittaciformes). Journal of Systematic Palaeontology 9(1):159-171.

Peters DS 1994. Messelastur gratulator n. gen. n. spec., ein Greifvogel aus der Grube Messel (Aves: Accipitridae). Courier Forschungsinstitut Senckenberg 170:3–9.

Shapiro B et al. (7 co-authors) 2002. Flight of the Dodo. Science Brevia 295:1683.

Turnstall M 1771. Ornithologica Britannica.

wiki/Falco
wiki/Didunculus
wiki/Tooth-billed_pigeon
wiki/Messelasturidae