#parapsittacopes

Passeriform birds are by far the most species rich bird group today, representing half of all birds (That's about 6,000 species), which is utterly wild. But before true passerines, birds in the stem-passerine lineage were already diversifying into all sorts of niches. They are equally close relatives to parrots and passeriforms, as can be seen from their passeriform-like bodies and beaks as well as their parrot-like zygodactyl feet. They were likely a big part of the Paleogene morning chorus.

Eofrillingirostrum: This Psittacopedid bird had a strong finch-like beak that was used in eating hard seeds. It lived during the early Eocene of Europe and North America.

Parapsittacopes: Another member of psittacopedes, this bird had a short beak used to eat fruit and berries. It lived 50 million years ago, and its fossils were found in the London Clay formation.

Eozygodactylus: This large member of the Zygodactylid family had long legs with parrot-like feet. These birds lived in North America during the early Eocene, 50 million years ago.

Sororavis: This rather strange member of the stem-passeriforms was found from the Fur Formation of Denmark, around 50 million years ago.

Pumiliornis: A long beaked stem-passeriform from Messel lake, around 40 million years ago. It was the first known bird to have eaten nectar, using its long beak to get it from flowers.

Primozygodactylus: Another member of the Zygodactylid group which lived all over Europe during the Eocene, but is best known from Messel Lake.

Psittacopes: A Psittacopedid bird with short legs and parrot-like feet. This frugivorous bird lived in many parts of Europe during the Eocene.

Psittacomimus: A Psittacopedid bird from the London Clay formation, this bird had zygodactyl feet like parrots as well as a short, rounded beak for eating seeds and fruit.

(Skull of Parapsittacopes bergdahli, from Mayr, 2021)

Meaning of name: Parapsittacopes = near Psittacopes [another Eocene bird that was likely a close relative]; bergdahli = for Paul Bergdahl [collector of the original fossil]

Age: Eocene (Ypresian), 54.6‒55 million years ago

Where found: London Clay Formation, Essex, U.K.

How much is known: Partial skeleton of one individual, including the skull and parts of all four limbs.

Notes: Parapsittacopes was likely a psittacopedid, a group of small (wren- to sparrow-sized) Eocene birds that were originally thought to have been closely related to parrots. Like parrots, they had two toes pointing forward and two backward on each foot. However, more recent studies suggest that psittacopedids might have been more closely related to passeriform birds (songbirds and their kin), which instead have the typical condition of modern birds in which three toes face forward and one points back.

Most previously known psittacopedid fossils were preserved as flattened remains, so the three-dimensionally preserved bones of Parapsittacopes reveal several previously unknown psittacopedid features. Some of these features provide further support for placing them as close relatives of passeriforms.

Psittacopedids exhibited a wide variety of beak shapes, and included probable seed-eating and nectar-eating species. The beak of Parapsittacopes was short and slightly widened, a common feature of birds that hunt insects in flight. Parapsittacopes may have caught insects by flying at them from a perch. It might have also fed on fruits.