Recognition of the zygodactyl parrots (Psittaciformes) as the closest extant relatives of passerines (Passeriformes) shed new light on the affinities of various Paleogene birds with a zygodactyl foot, which are now considered to be stem group representatives of the Passeriformes. However, most of these taxa are known only from compression fossils, which allow the recognition of a limited number of osteological details. Here, an exceptionally complete skeleton of a new species is described from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). Parapsittacopes bergdahli gen. et sp. nov. resembles Psittacopes lepidus (Psittacopedidae) from the Messel fossil site in Germany, from which it is distinguished in beak shape and several postcranial characters. Even though the phylogenetic analyses yielded conflicting tree topologies under different settings, all of the resultant phylogenies supported close affinities between Parapsittacopes, Psittacopes and the Eocene taxa Pumiliornis and Morsoravis. The three-dimensionally preserved bones of the P. bergdahli holotype exhibit subtle osteological characteristics of passeriform birds, which have not been reported from previously known fossils of closely related zygodactyl stem group taxa. The broad beak and low mandibular rami indicate that P. bergdahli may have caught insects by sallying flights from perches, and the new species therefore adds another feeding adaptation to the already diverse array of zygodactyl stem group Passeriformes with disparate feeding ecologies.

http://zoobank.org:pub:FD0E9DC4-961F-4460-9466-164E5EB42E4E

合子鹦鹉（Psittaciformes）是现存的雀形目（Passeriformes）最亲近的亲属，这为各种古近代鸟类与合子足的亲和力提供了新的亮点，这些鸟类现在被认为是Passeriformes的茎群代表。但是，大多数这些分类单元仅是从压缩化石中获悉的，这些压缩化石可以识别有限数量的骨科细节。在这里，从纳森河畔沃尔顿（英国埃塞克斯）的始新世伦敦粘土中描述了一个新物种的极其完整的骨骼。Parapsittacopes bergdahli根。等。十一月 类似于Psittacopes lepidus（Psittacopedidae）来自德国的梅塞尔化石遗址，以喙状和几个后颅骨特征而著名。即使系统发育分析在不同的环境下产生了相互矛盾的树形拓扑结构，但所有最终的系统发育支持Parapsittacopes，Psittacopes和始新世类群Pumiliornis和Morsoravis之间的密切亲和力。伯格达氏完整型的三维保存的骨骼展现出Passeriform鸟类的微妙的骨学特征，尚未从紧密相关的合子基茎类群的先前已知化石中报道。宽喙和下颌较低的罗姆人表明P. bergdahli 可能是由于栖息地的飞跃而捕获了昆虫，因此，新物种为已经多样化的具有不同饲养生态的of合半乳糖茎组Passeriformes增加了另一种饲养适应性。

http://zoobank.org:pub:FD0E9DC4-961F-4460-9466-164E5EB42E4E