Vescornis
Encyclopedia
Vescornis is a genus
of enantiornithine
bird. One species is named, V. hebeiensis. The holotype fossil is in the collection of the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences. Its catalog number is CAGS 130722. The fossil was found in Early Cretaceous
rocks first attributed to the Yixian Formation
, Senjitu, Fengning County, Hebei Province, China. However, later study of area geology showed that these rocks actually belong to the Huajiying Formation
.
Vescornis was described in detail by Zhang et al. in 2004.
, Vescornis, and "Hebeiornis", may be synonyms. If so, because the name Jibeinia was published in 1997, it would be the senior synonym and take priority. However, there is no consensus over whether or not they are actually synonyms, and some scientists continue to regard them as separate species.
When Vescornis was described in 2004, the authors noted that it was nearly exactly the same size as Jibeinia, and collected from the same locality. They noted several morphological similarities to Jibeinia but, also, distinct differences in some characters from the written description. They sought to compare the two specimens but learned from Dr. Hou in 2001 that the holotype Jibeinia had been lost, and existing casts were of too poor a quality to be decisive. Thus they conclude that it will be impossible to verify whether the two are the same species, unless the holotype of Jibeinia is rediscovered.
The name "Hebeiornis" was published in 1999, based on the same specimen as Vescornis (CAGS 130722). However, the describers (Xu et al.) gave little anatomical detail and few comparisons to other taxa, and later researchers have concluded that this was not an adequate description to establish the new name, and it is now regarded as a nomen nudum
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of enantiornithine
Enantiornithes
Enantiornithes is an extinct group of primitive birds. They were the most abundant and diverse avialans of the Mesozoic. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over 50 species of Enantiornithines have been named, but some...
bird. One species is named, V. hebeiensis. The holotype fossil is in the collection of the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences. Its catalog number is CAGS 130722. The fossil was found in Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
rocks first attributed to the 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...
, Senjitu, Fengning County, Hebei Province, China. However, later study of area geology showed that these rocks actually belong to the Huajiying Formation
Huajiying Formation
The Huajiying Formation is a geological formation in Hebei, People's Republic of China. Known for its fossils including primitive birds, the age of the ormation is uncertain. It may represent an early portion of the Jehol Biota, dating to somewhere in the early Cretaceous or late Jurassic periods...
.
Vescornis was described in detail by Zhang et al. in 2004.
Possible synonyms
The three taxa JibeiniaJibeinia
Jibeinia is a Genus of enantiornithine bird. Only one species is known, Jibeinia luanhera. It is known from one holotype fossil found in the Liaoning province, People's Republic of China. This fossil is now lost...
, Vescornis, and "Hebeiornis", may be synonyms. If so, because the name Jibeinia was published in 1997, it would be the senior synonym and take priority. However, there is no consensus over whether or not they are actually synonyms, and some scientists continue to regard them as separate species.
When Vescornis was described in 2004, the authors noted that it was nearly exactly the same size as Jibeinia, and collected from the same locality. They noted several morphological similarities to Jibeinia but, also, distinct differences in some characters from the written description. They sought to compare the two specimens but learned from Dr. Hou in 2001 that the holotype Jibeinia had been lost, and existing casts were of too poor a quality to be decisive. Thus they conclude that it will be impossible to verify whether the two are the same species, unless the holotype of Jibeinia is rediscovered.
The name "Hebeiornis" was published in 1999, based on the same specimen as Vescornis (CAGS 130722). However, the describers (Xu et al.) gave little anatomical detail and few comparisons to other taxa, and later researchers have concluded that this was not an adequate description to establish the new name, and it is now regarded as a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
.