[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Details on Jibeinia II
Holotype- (IVPP collection; lost)
At least my thesis doesn't lose anything (I need full-grown specimens).
Sterna alone is the plural.
(Not that it matters, of course. The term is made up. I've seen
interclavicles called episterna, but that's all.)
Interestingly, if manual phalanx III-1 is actually a broken piece of
metacarpal III, both the apparently short metacarpal III and presence of
three phalanges on that digit would be resolved and the manus would
resemble those of other enantiornithines.
When summed up, Jibeinia is most likely to be a basal cathayornithid of
Eoenantiornis-Sinornis grade. The discordant characters are almost all
potentially ontogenetic and due to Jibeinia's juvenile age. Not only are
more basal positions less parsimonious, but the discordant characters are
not those that could be explained by ontogeny, making such positions even
more unlikely. For instance, a position sister to Protopteryx (as has been
suggested by Zhou and Zhang, 2005) is at least 7 steps longer, even if the
probably shared juvenile characters of Jibeinia and Protopteryx are
as true synapomorphies.
Would have been great to have an intermediate between Confuciusornithidae
and Ornithothoraces. I guess it was not to be.
Zhang et al. (2004) suggested Jibeinia may be a senior synonym of
(described by those authors as Vescornis), which they described from the
same formation. This was based on their identical size and numerous
characteristics. Indeed, it only takes one more step to place Jibeinia as
basal gobipterygid related to Hebeiornis.
Besides those characters listed in
the diagnosis, Jibeinia differs from Hebeiornis in- more shallow anterior
dentary; elongate posteromedial sternal processes; narrow ventral tubercle
of humerus; larger manual ungual I.
Are those visible in the photos of *Jibeinia*?
References- Hou, 1997. Mesozoic Birds of China. Phoenix Valley Bird Park,
A wild mixture of transcriptions...