Pengornithidae is a group of early

enantiornithines The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and cla ...

from the early

Cretaceous Period The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of t ...

of China, with the putative member '' Falcatakely'' possibly extending this clade's range into the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

, and several putative pengornithids also hail from this formation.O'Connor and Forster, 2010. A Late Cretaceous (Maastrichtian) avifauna from the Maevarano Formation, Madagascar. Journal of Vertebrate Paleontology. 30(4), 1178-1201. Specimens of these animals have been found both in the

Huajiying Formation The Huajiying Formation is a geological formation in Hebei, People's Republic of China. Known for its fossils including feathered dinosaurs, the age of the formation is uncertain. It may represent an early portion of the Jehol Biota, dating to s ...

and

Jiufotang Formation The Jiufotang Formation ( Chinese: 九佛堂组, pinyin: ''jiǔfótáng zǔ'') is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see ...

of Liaoning and

Hebei Hebei or , (; alternately Hopeh) is a northern province of China. Hebei is China's sixth most populous province, with over 75 million people. Shijiazhuang is the capital city. The province is 96% Han Chinese, 3% Manchu, 0.8% Hui, and 0 ...

provinces, dating from the

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the ...

age (130.7 million years ago) to the Aptian age (120 million years ago).

Description

Pengornithids were basal enantiornithes. They had many small teeth in their jaws, and stout legs. Their internal anatomy was characterized by a hooked outgrowth of the shoulder blade and a

pygostyle Pygostyle describes a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main compone ...

(the tail bone to which long feathers attach) which was short and rounded, instead of long and blade-shaped as in other enantiornithes. While most enantiornithes had four long backward projections growing from their breastbones, pengornithids only had two. Assuming ''Falcatakely'' is a pengornithid, it exhibits a rather novel cranial morphology compared to other enantiornitheans, having a

toucan Toucans (, ) are members of the Neotropical near passerine bird family Ramphastidae. The Ramphastidae are most closely related to the American barbets. They are brightly marked and have large, often colorful bills. The family includes five g ...

-like snout ending on small teeth.

Ecology

The unique, rounded pygostyle and long, stiff tail feathers of pengornithids would have made their tail overall similar to that of

woodpecker Woodpeckers are part of the bird family Picidae, which also includes the piculets, wrynecks, and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar, and the extreme polar regions. ...

s. The feet of pengornithids were also particularly adapted for grasping branches. These features indicate that while pengornithids may not have been as adept at climbing as many modern

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 ...

s, they were better climbers than many other enantiornithes. ''Falcatakely'' has been compared to

toucans Toucans (, ) are members of the Neotropical near passerine bird family Ramphastidae. The Ramphastidae are most closely related to the American barbets. They are brightly marked and have large, often colorful bills. The family includes five g ...

due to similar snout morphology.

Classification

The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

below was found in the phylogenetic analysis of Hu ''et al.'' 2014. The

below was found by an analysis by Wang ''et al.'' in 2015, updated from a previous data set created by Jingmai O'Connor.

References

{{Taxonbar, from=Q20072368 Enantiornitheans Early Cretaceous birds of Asia Prehistoric dinosaur families