Precursor (bird)

"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]

"Precursor" Temporal range: Ypresian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Superorder:	Neoaves
Order:	see text
Genus:	"Precursor" Harrison & Walker, 1977
Species
"Precursor" parvus Harrison & Walker, 1977 (type) "Precursor" litorhinus Harrison & Walker, 1977 "Precursor" magnus Harrison & Walker, 1977 but see text

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]