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Hebeiornis the valid name for Vescornis

I was recently sent a pdf of the description of Hebeiornis fengningensis, previously mentioned by Jerry- http://dml.cmnh.org/2005Nov/msg00108.html . Using Babelfish to translate the Chinese text, it became apparent this is a terribly written paper. The Yixian Formation is referred to the Jurassic. There's a basic lack of details regarding the anatomy of Hebeiornis, with around ten morphological features noted along with measurements or several elements. The description of the pose of the specimen is approximately as long. The summary of the world's main Mesozoic bird taxa includes only Archaeopteryx, Cathayornis "shanwangensis" (a presumed misspelling), Hesperornis and Ichthyornis. After a brief rundown of the characters found in Odontornithes, Palaeognathae, Neognathae and Archaeopteryx, Hebeiornis is concluded to be most similar to Archaeopteryx (it has teeth, lacks a prominent keel and supposedly a pygostyle), but more derived because of the partially fused carpometacarpus. The paper was written in 1998, but none of the references are more recent than 1986, nor involve birds. Hebeiornis is listed as gen. et sp. nov. and attributed to Yan, 1999, which I assume to mean they are the only author (perhaps a mispelling of Yang You-shi?) taking credit for the name, as opposed to there being a separate Yan, 1999 publication. This would all just be a sad, if interesting, case of an indeterminate Yixian bird if not for the fact a photograph is included.

The photograph is extremely poor, and only labeled "Bird fossils in the bottom of the Jurassic Yixian Formation". However, only one Yixian bird specimen is described in the paper, and the pose described for Hebeiornis is the same (complete specimen exposed ventrally, neck curving to its left, deflected skull). The important thing is that this is obviously a photograph of the holotype of Vescornis hebeiensis! The latter taxon is of course also from the Yixian Formation of Senjitsu in Fengning County. The measurements match fairly well with Vescornis (skull ~24 vs. 27 mm; scapula ~17 vs. 13 mm; humerus ~24 vs. 25 mm; ulna ~25 vs. 30 mm; femur ~24 vs. 25 mm; tibia ~30 vs. 30 mm), as do the few osteological details with the exception of the pygostyle. As Babelfish translates, Hebeiornis "does not have the tail synthesis bone", while Vescornis has a pygostyle. Then again, the authors were apparently unfamiliar with the numerous basal pygostylians with elongate pygostyles (with the exception of Cathayornis, which they never discuss, only list), so perhaps Vescornis' elongate pygostyle was too dissimilar to ornithurine sensu stricto pygostyles for them to count it? Or perhaps it's just another failing of a poor description or translation.

So accepting the two names are based on the same specimen, Hebeiornis clearly has chronological priority by five years. But is it valid? After reading the revelent articles of the ICZN, I believe it is. The publication is valid. There is a description that purports to differentiate the taxon from other taxa, as poor as it may be. Can anyone find a reason the name is invalid (remember it was published in 1999, so the post-1999 rules do not apply)? I see no choice but to sink Vescornis hebeiensis as an objective junior synonym of Hebeiornis fengningensis, despite the fact the former has one of the most detailed and well illustrated descriptions of any Yixian bird and was written by three coauthors who are quite knowledgable on the subject. Gotta love the principle of priority. Maybe someone should petition the ICZN?

Xu, G.-L., Y.-S. Yang, and S.-Y. Deng. 1999. First discovery of Mesozoic bird fossils in Hebei Province and its significance. Regional Geology of China 18(4):444-448.

Mickey Mortimer