Boluochia closely related to longipteryx, study shows

Apr 06, 2011
Figure 1. Photograph of the holotype of Longipteryx chaoyangensis (IVPP V12325). Scale bar represents 1 cm. Credit: O’Connor JK

Very little was known about Mesozoic birds until nearly complete skeletons began to be discovered in the now famous Jehol Group deposits of northeastern China.

The first few specimens to be found were partial skeletons, most preserving only the voids of the bones. Over the past two decades, new specimens have continued to be uncovered at an uprecedented rate. More recent published discoveries have typically been complete, including , and benefited from recent advances in preparational techniques, thus providing a huge wealth of data regarding species diversity in northeastern during the Early Cretaceous and the greatest wealth of data on Mesozoic birds anywhere in the world. Using this new data, a renewed look at the first few Jehol birds to be described reveals new information.

Paleornithologists of the Institute of and (IVPP), Chinese Academy of Sciences, post-doctor Jingmai O’Connor, Director Zhou Zhonghe, and researcher Dr. Zhang Fucheng, reinvestigated Boluochia zhengi, one of the first birds described from the Jehol deposits. This taxon is very fragmentary, preserving clearly only the ankles and feet, however, this detailed study revealed that this species can now be assigned to the most diverse recognized group of enantiornithines, the Longipterygidae. Other members of this group (Longipteryx, Longirostravis, Shanweiniao and Rapaxavis) are all known from nearly complete specimens and preserve elongate rostra with teeth restricted to the tips of their jaws. This is interpreted as a trophic specialization that would have made food items available to members of this clade that were inaccessible to other , and may have contributed to their evolutionary success evident from their high . Although only a few fragments of the skull are preserved in the only known specimen of Boluochia, O’Connor, Zhou and Zhang were able to identify subtle clues that hint at the presence of an elongate rostrum in this taxon as well. These, however, could not be recognized until more complete specimens were discovered and available for comparison.

Figure 2: Photographs of the holotype of Boluochia zhengi (IVPP V9770). Credit: O’Connor JK

There are two lineages of longipterygids: those that are smaller with reduced hands (Longirostravis, Shanweiniao and Rapaxavis), and a more basal lineage with large claws on the hands and large teeth, before only represented by Longipteryx. Among longipterygids, O’Connor, Zhou and Zhang determined that the preserved morphology most closely aligns Boluochia with Longipteryx; unfortunately both taxa are from the younger Jiufotang Formation, and basal longipterygids (those with primitive morphologies such as claws on the hands such as Longipteryx) remain unknown from the older Yixian formation that has produced the apparently more derived Longirostravis and Shanweiniao. Boluochia and Longipteryx share an unusual morphology of the foot, with metatarsals III and IV subequal in length, and a very large and robust pygostyle (the distal tail ). However, Boluochia can still be distinguished from Longipteryx and the two remain separate species based on the outwards deflection of the outermost foot bone (distal end of metatarsal IV).

Explore further: Lead in teeth can tell a body's tale

Provided by Institute of Vertebrae Paleontology and Paleoanthropology

4 /5 (3 votes)
add to favorites email to friend print save as pdf

Related Stories

The skull of extinct birds revealed

Mar 21, 2011

Birds are the most diverse clade on the planet, and the skull of the living bird is one of the most highly modified and morphologically variable regions of their skeleton. The large diversity of enantiornithine ...

Earliest toothless bird found

Dec 10, 2009

(PhysOrg.com) -- A new species of bird from the Cretaceous period in China has been identified. It had toothless upper and lower jaws, and provides significant information on the diversification in the evolution ...

Prehistoric bird fossil found in China

Dec 15, 2005

The fossil of a previously unknown water bird that lived some 125 million years ago has been found in sandstone near Inner Mongolia in northeast China.

What's in a dinosaur name?

Sep 17, 2008

(PhysOrg.com) -- A new species of dinosaur is named somewhere in the world every two weeks. But are they all new species, or do the newly-discovered bones really belong to a dinosaur already identified?

Recommended for you

Shrinking dinosaurs evolved into flying birds (w/ Video)

4 hours ago

A new study involving scientists from the University of Southampton has revealed how massive, meat-eating, ground-dwelling dinosaurs evolved into agile flying birds: they just kept shrinking and shrinking, ...

Fragment of Ice Age ivory lion gets its head back

11 hours ago

Archaeologists from the University of Tübingen have found an ancient fragment of ivory belonging to a 40,000 year old animal figurine. Both pieces were found in the Vogelherd Cave in southwestern Germany, ...

Violent aftermath for the warriors at Alken Enge

Jul 29, 2014

Denmark attracted international attention in 2012 when archaeological excavations revealed the bones of an entire army, whose warriors had been thrown into the bogs near the Alken Enge wetlands in East Jutland ...

User comments : 0