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Re: Vorona's claw does it exist?



ekaterina amalitzkaya wrote-

> Vorona was said
> to be a typical enantiornithine there was no reason to believe otherwise.
So
> is this sickle claw merely an error of Mr. Keesey or some new material of
> Vorona that has become available? I remeber that there was a south
American
> enantiornithine with raptorial claws (could some one give its name?)
> descibed several years ago- but the was a convergent feature with quite
> different structure from the claw of the dromeosaurs. Finally has evidence
> for this claw ever turned up in oviraptorosaurus?

As several have already said, Vorona lacks evidence for a sickle claw,
although no pedal remains are known.  There is nothing showing Vorona is an
enantiornithine, it was described as being in a trichotomy with
enantiornithines and euornithines.  Still, it is possible future studies
will show that it belongs to the Enantiornithes.  The South American bird
you're remembering is Patagopteryx.  Chiappe et al. (1999) state- "...the
predatorial specializations of digit II ... retained to a lesser degree in
certain more advanced birds, such as Patagopteryx deferrariisi (Chiappe,
1996)."  Unfortunately, I have yet to get Chiappe 1996, although I plan to
soon.  Jaime did a good job saying no predatory specializations are known
for oviraptorosaurs.

Fred Ruhue wrote-

>If I remember correctly, the raptorial enantiornithine was Boluochia zhengi
>Zhou, 1995. from China (Liaoning).

Boluochia has disarticulated pedes, but the unguals are all subequal in
size.  There is also no mention by the authors that it had a sickle claw.
Boluochia does have a raptorial beak, which is what Fred was no doubt
thinking of.

Jaime Headden wrote-

>[?]     Archaeopteryx (A. lithographica and A. bavarica)
>          [Paul suggests that the claw was extensible, other
>         workers who have looked for the features suggest the
>          phalanges are either not indicating this
>          extensibility, or the phalanges were inverted upon
>          observation; I have no opinion on the subject]

See this for all the details-
http://www.cmnh.org/fun/dinosaur-archive/2001Jan/msg00121.html

>[?]     Confuciusornis sanctus [this taxon may have a
>          extensible claw, but the claw itself does not appear
>          to be "raptorial" or sickle-shaped]

Chiappe et al. (1999) in their monograph of confuciusornithids state,
"Confuciusornis sanctus lacks the predatorial specializations of digit II
seen in Rahonavis ostromi and retained to a lesser degree in certain more
advanced birds, such as Patagopteryx deferrariisi."
And, "This (the hallux) and the remaining ungual phalanges bear well
developed flexor tubercles and are approximately the same size."
(parentheses mine)
And, "The distal trochlea of metatarsal II also lacks a ginglymoideal
articulation."
Personal examination of figure 45 in that publication indicates that pedal
ungual II is a whopping 5% larger than pedal ungual III, while pedal ungual
IV is 5% shorter.

Mickey Mortimer