''"Precursor"'' is a controversial prehistoric

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

from the Early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

. It was established based on

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s found in

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, including in the famous

London Clay The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from t ...

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. These remains were originally considered to be members of the

Charadriiformes Charadriiformes (, from '' Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water ...

, more specifically the earliest representatives of the

Glareolidae Glareolidae is a family of birds in the wader suborder Charadrii. It contains two distinct groups, the pratincoles and the coursers. The atypical Egyptian plover (''Pluvianus aegyptius''), traditionally placed in this family, is now known to ...

(

pratincole The pratincoles or greywaders are a group of birds which together with the coursers make up the family Glareolidae. They have short legs, very long pointed wings and long forked tails. Description Their most unusual feature for birds classed as ...

s and

courser The coursers are a group of birds which together with the pratincoles make up the family Glareolidae. They have long legs, short wings and long pointed bills which curve downwards. Their most unusual feature for birds classed as waders is that ...

s). However, several authors have since found this interpretation to be dubious, with the lack of measurements and contradictory wording making the original description's conclusions difficult to verify. 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 Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushr ...

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittaco ...

s The remains of which (including a complete skeleton) were found in the Green River Formation in the United States.

References

Prehistoric bird genera Eocene birds Glareolidae Pseudasturidae Controversial bird taxa Prehistoric birds of Europe Fossil taxa described in 1977 {{paleo-bird-stub