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Re: Parahongshanornis, new Chinese Cretaceous bird (free pdf)
firstname.lastname@example.org <email@example.com> wrote:
> LI Li, WANG Jing-Qi, & HOU Shi-Lin (2011)
> A NEW ORNITHURINE BIRD (HONGSHANORNITHIDAE) FROM THE JIUFOTANG FORMATION OF
> CHAOYANG, LIAONING, CHINA.
> Vertebrata Palasiatica 49(2): 195-200
Aside from the name, which is truly inspired ('_Parahongshanornis_'),
the other notable thing about this bird is the length of the humerus,
which is shorter than the ulna (humerus/ulna = 1.07). This is
characteristic of hongshanornithids (_Hongshanornis_ = 1.08;
_Longicrusornis_ = 1.04), as well as modern members of the Gruiformes
and Ciconiiformes (based on Nudds et al., 2004). Hongshanornithids
also have long legs, and are thought to have been waders.
Having a humerus/ulna ratio substantially more than 1 was one of the
features used by Chiappe et al. (2006) to argue that the
enantiornithean _Elsornis_ was secondarily flightless. _Elsornis_ has
a humerus/ulna ratio of about 1.16, which is almost identical to that
of _Archaeopteryx_. But many modern Anseriformes and Coliiformes have
ratios around this value too. Granted, Chiappe &c didn't *only* use
the high humerus/ulna ratio to argue that _Elsornis_ didn't fly; the
shape of the humerus, and overall total arm length against forearm
length ratio, were cited in support as well. But modern ratites have
a humerus/ulna ratio of up to 2 or 3, a far cry from 1.2.