''Cuspirostrisornis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

enantiornithean 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 ...

bird. Only one species is known, ''Cuspirostrisornis houi'', though some researchers believe this to be a synonym of the similar species '' Cathayornis yandica''.Zhou Z. and Wang Y. (2010). "Vertebrate diversity of the Jehol Biota as compared with other lagerstätten." ''Science China: Earth Sciences'', 53(12): 1894–1907.

It is known from one

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

found in the

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 ...

Liaoning Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...

province,

People's Republic of China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. The

is dated to the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period,

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 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

age, 120.3 +/-0.7 million years ago.He, H.Y., Wang, X.L., Zhou, Z.H., Wang, F., Boven, A., Shi, G.H., Zhu R.X. (2004). "Timing of the Jiufotang Formation (Jehol Group) in Liaoning, northeastern China, and its implications". ''Geophysical Research Letters'' 31(13): 1709. ''C. houi'' is known from a nearly complete fossil. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

fossil is in the collection of the

Institute of Vertebrate Paleontology and Paleoanthropology The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name suggest ...

in Beijing, China. The fossil is given catalog number IVPP V 10897. It was collected in 1993 by Dr. Hou Lianhai and Hou Jinfeng, the illustrator at IVPP. It was collected from light gray mudstones approximately two kilometers west of Boluochi Village, Chaoyang County, Liaoning Province.Hou, Lianhai (1997)
Mesozoic Birds of China
Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China. Published by the Phoenix Valley Provincial Aviary of Taiwan. In Chinese, translated by Will Downs, Bilby Research Center, Northern Arizona University, January, 2001. The holotype fossil is that of a small perching bird, with a skull about 27 millimeters (1 inch) long. There are five pairs of tiny teeth in the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

, and another five pairs in the anterior

dentary In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

. It had a pointed snout which Hou identified as a beak proportionally similar to the beaks of the extant

'' Motacilla'', the wagtails. However, some have noted that there is no evidence that the snouts of tooth-bearing prehistoric birds such as most enantiornitheans would also have possessed a horny beak, at least in a toothed part of the snout. As ''Cuspirostrisornis'' had a toothed snout, the beak which Hou presumed was present in the genus is likely a misinterpretation, similar to the hooked beak which was erroneously stated to be present in ''

Boluochia ''Boluochia zhengi'' was an enantiornithine bird. It lived during the Early Cretaceous in the time span 121.6-110.6 mya ( late Aptian- early Albian) and is known from fossils found in the Jiufotang Formation of Liaoning province, People's Republ ...

'', one of many other enantiornitheans described in the same paper. The ulna is large and derived, with the s-shape of modern flying birds. The sternum is large,

carinate Carinate is a shape in pottery, glassware and artistic design usually applied to amphorae or vases. The shape is defined by the joining of a rounded base to the sides of an inward sloping vessel. This design is seen in ancient cultures such as ...

, and broad.

Etymology

The generic name comes from the Latin words for "pointed" and "beak", and the specific name refers to its describer, Mr. Hou Jinfeng, who is mentioned above.

References

Avisaurids Bird genera Early Cretaceous birds of Asia Fossil taxa described in 1997 Jiufotang fauna {{paleo-bird-stub