''Perplexicervix'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of perplexicervicid

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

that lived during the

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

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

. Its affinities are uncertain but similarities with Otidiformes were noted in tentatively assigned

postcranial The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

remains.

Distribution

''P. paucituberculata'' remains hail from the Walton Member of the

London Clay Formation The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 54-50 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 the ...

and date back to the

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

. ''P. microcephalon'' appears in the eleventh Mammal-Paleogene zone of

Hessen Hesse or Hessen ( ), officially the State of Hesse (), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt, which is also the country's principal financial centre. Two other major historic cities are Da ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

, its

fossils 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 ...

having been found in the

Messel Formation The Messel Formation is a geologic formation in Hesse, central Germany, dating back to the Eocene epoch (about 47 Ma). Its geographic range is restricted to the Messel pit. There it unconformably overlies crystalline Variscan basement and ...

References

Fossils of Germany Neognathae Eocene birds {{paleo-bird-stub