Longipterygidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of early enantiornithine bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s from the early Cretaceous Period of China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. All known specimens come from the Jiufotang Formation

Jiufotang Formation

The Jiufotang Formation is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms. . It is a member of the Jehol group. The exact age of the Jiufotang has been debated for years, with...

 and Yixian Formation

Yixian Formation

The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...

, dating to the early Aptian

Aptian

The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...

 age, 122-120 million years ago.

Description

Longipterygids are characterized by an extremely long, toothed snout (making up over 60% of the total skull length), in which the teeth are restricted to the tips of the jaws. The snouts were straight but slightly concave at a point behind the nostrils, and the bones of the snout tip were solid. Their pygostyle

Pygostyle

Pygostyle refers to a number of the final few caudal vertebrae fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these....

s, the series of fused vertebrae in the tail, were unusually large, and longer than the foot bones. The feet of longipterygids were also specialized relative to other enantiornithines. Where most ennantiornithines had a long middle tow with a "knuckle" (trochlea

Trochlea

Trochlea is a term in anatomy. It refers to a grooved structure reminiscent of a pulley's wheel.Most commonly, trochleae bear the articular surface of saddle and other joints:* Trochlea of humerus* Trochlear process of the Calcaneus...

) that extended beyond the outer two, the toes of longipterygids were even in length, and attached to the rest of the foot at the same level. This configuration is also seen in some groups of modern birds and is usually considered an adaptation for advanced perching ability. It is likely that longipteryigids lived primarily in trees. Because their long jaws tipped with large, often curved teeth are usually considered an adaptation for catching and eating fish, it is likely that they were similar in ecology to modern Kingfisher

Kingfisher

Kingfishers are a group of small to medium sized brightly coloured birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species being found in the Old World and Australia...

s.

Classification

Cladogram

Cladogram

A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...

 based on O'Connor, Gao and Chiappe (2010a) & You et al. (2010b):