"Precursor" is a controversial prehistoric bird genus from the Early Eocene.^[1][2] It was established based on fossils found in England, including in the famous London Clay deposits. Three species are included in the genus: "P." parvus, the type species, "P." magnus, and "P." litorum, all named by Colin Harrison and Cyril Walker in 1977.^[1][3]

These remains were originally considered to be members of the Charadriiformes, more specifically the earliest representatives of the Glareolidae (pratincoles and coursers).^[1] However, several authors have since found this interpretation to be dubious,^[2][4] with the lack of measurements and contradictory wording making the original description's conclusions difficult to verify.^[5] At least some of the material, namely the paratype humerus of "P." parvus, has been re-interpreted as belonging to the Pseudasturidae (or Halcyornithidae), a group of stem-parrots, the remains of which (including a complete skeleton) were found in the Green River Formation in the United States.^[6][7]

v t e Genera of shorebirds and their extinct allies
Kingdom: Animalia Phylum: Chordata Class: Aves Infraclass: Neognathae Clade: Neoaves Order: Charadriiformes
Charadriiformes incertae sedis †Charadriisimilis †Eupterornis? †Fluviatitavis? †Jiliniornis †"Morsoravis" †Nahmavis †Palintropus? †Sarjeantopodus †Scandiavis †Volgavis? †Laornithidae? Laornis †Graculavidae? Dakotornis Graculavus Palaeotringa Telmatornis? Charadrii See below ↓ Scolopaci See below ↓ Lari See below ↓
Charadrii incertae sedis †Cherevychnavis Burhinidae Burhinus Esacus †Genucrassum Pluvianellidae Pluvianellus Chionidae Chionis †Chionoides †Neilus Pluvianidae Pluvianus Pluvianidae Vanellinae †Dolicopterus? Erythrogonys Hoploxypterus Vanellus †Viator Charadriinae Anarhynchus Charadrius †Dorypaltus Elseyornis †Jilniornis Oreopholus Peltohyas Phegornis Pluvialis Thinornis Recurvirostridae Cladorhynchus Himantopus †Kashinia Recurvirostra Ibidorhynchidae Ibidorhyncha Haematopodidae Haematopus
Scolopaci incertae sedis †Hakawai †Scolopacimilis Jacanidae Actophilornis Hydrophasianus Irediparra Jacana †Janipes Metopidius Microparra †Nupharanassa Pedionomidae †Oligonomus Pedionomus Rostratulidae Nycticryphes Rostratula Scolopacidae Actitis Arenaria Bartramia Calidris Coenocorypha †Elorius Gallinago Limnocryptes Limnodromus Limosa †Mirolia Numenius †Nuntius †Paractitis †Parvelorius Phalaropus Prosobonia Scolopax Tringa †Villetus Xenus Thinocoridae Attagis Thinocorus
Lari Alcidae †Divisulcus †Hydrotherikornis †Miocepphus †Pseudocepphus Alcinae Alcini Alca Alle †Pinguinus Uria Synthliboramphini Synthliboramphus Cepphini Cepphus Brachyramphini Brachyramphus Fraterculinae Aethiini Aethia Ptychoramphus Fraterculini Cerorhinca Fratercula †Mancallinae Alcodes Mancalla Miomancalla Praemancalla Dromadidae Dromas Glareolidae †Becassius †Boutersemia †Mioglareola †Paractiornis †"Precursor"? Glareolinae Glareola Stiltia Glareolinae Cursorius Rhinoptilus Laridae Anous Chlidonias Chroicocephalus Creagrus †Feducciavis †Gaviota Gelochelidon Gygis Hydrocoloeus Hydroprogne Ichthyaetus †Laricola Larosterna Larus Leucophaeus †Limicolavis? †Limosavis Onychoprion Pagophila Phaetusa †Pseudosterna Rhodostethia Rynchops Rissa Sterna †Sternalara Sternula Thalasseus Xema Stercorariidae Stercorarius Turnicidae †Cerestenia †Eocliffia? Ortyxelos †Turnipax Turnix