''Parapsittacopes'' is an extinct genus of psittacopedid bird from the

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

London Clay, United Kingdom. The genus contains one species, ''Parapsittacopes bergdahli''.

Discovery and naming

The holotype of ''Parasittacopes'' was collected from the London Clay near Walton-on-the-Naze by Paul Bergdahl of Kirby-le-Soken, a private collector. The specimen later became available to science with the help of Bergdahl's son, and is designated SMF Av 653. The specimen consists of a partial skeleton, including the skull, some of the jaw bones, several vertebrae, parts of the scapula, coracoid, and furcula, parts of many wing bones, and significant portions of the legs and feet. In 2020, ''Parapsittacopes bergdahli'' was described as a new genus and species of psittacopedid by Gerald Mayr. The generic name is from Greek ''para'', meaning "next to", and ''Psittacopes'', the type genus of the Psittacopedidae to which ''Parapsittacopes'' is referred. The specific ephitet ''bergdahli'' is after Paul Bergdahl, the collector who initially discovered and excavated the holotype. In 2022, additional material of the specimen NMS.Z.2021.40.43 was referred to ''Parapsittacopes''. This specimen preserves bones of the wings, including parts of the ulnae, a radius, portions of the humerus, a left coracoid, part of a scapula, and several bones of the manus.

Description

''Parapsittacopes'' was a moderately small bird, about the size of the Speckled mousebird (''Colius striatus''). The upper beak is less than half the length of the skull as a whole, and is short and wide. The openings of the nostrils are very large. The beak is comparable to that of the Bohemian waxwing (''Bombycilla garrulus''). The coracoid bears a large procoracoid process, protruding from the side of the bone, and does not have a foramen for the supracoracoid nerve but rather a groove. The keel has a sharply pointed tip which protrudes forward. The humerus is short and wide, resembling that of mousebirds. The ulna is longer than the radius. In the pelvis, the

ilium Ilium or Ileum may refer to: Places and jurisdictions * Ilion (Asia Minor), former name of Troy * Ilium (Epirus), an ancient city in Epirus, Greece * Ilium, ancient name of Cestria (Epirus), an ancient city in Epirus, Greece * Ilium Building, a ...

is not co-ossified with the

synsacrum The synsacrum is a skeletal structure of birds and other dinosaurs, in which the sacrum is extended by incorporation of additional fused or partially fused caudal or lumbar vertebrae and it can only be seen in birds. Some posterior thoracic vert ...

, a condition rare in modern arboreal birds. The femur is relatively long. There is a depression of the trochlea of the third toe and a splayed trochlea of the fourth toe, indicating that ''Parapsittacopes'' had a zygodactyl foot arrangement.

Classification

''Parapsittacopes'' was a member of the Psittacopedidae, a family of small birds that are likely a stem lineage related to the Passeriformes, the songbirds. Cladogram after analyses based solely on morphological data, Mayr (2020): However, this morphological analysis does not agree with studies based on DNA. When constrained to those molecular results, ''Parapsittacopes'', along with the rest of the Psittacopedidae, were found to be most closely related to a clade of the Passeriformes and the

Zygodactylidae Zygodactylidae is a family of extinct birds found in Europe and North America from the Eocene epoch to the Middle Miocene. First named in 1971, based on fragmentary remains of two species from Germany, a more complete description of the birds bec ...

, another extinct family of small arboreal birds of the Eocene.

Palaeobiology

''Parapsittacopes'' had a unique beak shape among the Psittacopedidae, which may be compared to extant birds: large nostrils and the curve of the beak resemble that of

swifts Swift or SWIFT most commonly refers to: * SWIFT, an international organization facilitating transactions between banks ** SWIFT code * Swift (programming language) * Swift (bird), a family of birds It may also refer to: Organizations * SWIFT, ...

and

treeswift Treeswifts or crested swifts are a family, the Hemiprocnidae, of aerial near passerine birds, closely related to the true swifts. The family contains a single genus, ''Hemiprocne'', with four species. They are distributed from India and Southeast ...

s, while the outline of the bill is similar to that of

waxwing The waxwings are three species of passerine birds classified in the genus ''Bombycilla''. They are pinkish-brown and pale grey with distinctive smooth plumage in which many body feathers are not individually visible, a black and white eyestripe, ...

s. This beak shape indicates that ''Parapsittacopes'' might have eaten fruit and caught insects by flying out from a perch. The resemblance in beak shape to swifts and treeswifts suggest that ''Parapsittacopes'' primarily ate insects. Unlike in modern songbirds and in the Zygodactylidae, ''Psittacopes'' has short legs, which might indicate that it walked on trees on the ground less than songbirds, rather choosing to remain perched on branches. The beak shape of ''Psittacopes'' also provides insight into the disappearance of birds like it and ''

Psittacopes ''Psittacopes'' is an extinct genus of bird from Middle Eocene. One species is recorded from Messel, Germany (''P. lepidus''), and other three possible species are from London Clay, England, one named ''?Psittacopes occidentalis'' in 2022, and t ...

''. These birds had specialised diets and feeding styles, as shown by the variety of beak types they had. This could have made them more vulnerable to competition, facilitating the replacement of this family, one of the first kinds of neornithean to be small and arboreal.

References

{{Taxonbar, from=Q123347030 Prehistoric bird genera Eocene birds of Europe Psittacopedidae