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Re: Birds of Russia and Mongolia



First of all, thanks for this great post!

>> Boluochia apparently differs in having subequal medial and lateral
condyles.  The issues involving using single traits to classify taxa and of
Boluochia's position as an enantiornithine should be evident, but this is
not the place to discuss them.<<

I hardly know more of *Boluochia* than its name... what are the problems of
its classification?

> Volgavis Nessov and Yarkov 1989
> V. marina Nessov and Yarkov 1989
> Danian, Paleocene
> unnamed formation, Volgograd, Russia
> Comments- This taxon was originally thought to be from the Late
Maastrichtian, but the deposits where it was discovered are now thought to
be Danian.

Cool!

> Gobipteryx Elzanowski 1974
> G. minuta Elzanowski 1974
> Late Campanian, Late Cretaceous
> Baruungoyot Formation, Mongolia

Double u now?
(However, there are always surprises with Mongolian... I have a copy of one
Joint Soviet-Mongolian Expedition issue, where all papers are in Russian,
the title page and the table of contents are in Mongolian, Russian and
English, and there are English summaries. It turns out that the place the
Russians call Udan Sayr [replace j for y or whatever you like] is Üüden Sayr
in Mongolian.)

>>Besides N? valifanov, Boluochia is the only other enantiornithine with a
toothless premaxilla.  It differs in having a decurved beak with a convex
ventral margin posteriorly and a toothed dentary.<<

It has teeth? Are these serrated? :-9

>>Enantiornithes indet.
Late Campanian, Late Cretaceous
Baruungoyot Formation, Mongolia
Material- (ZPAL MgR-1/33; ZPAL MgR-1/34; ZPAL MgR-1/88) embryos
Gobipipus Chatterjee, Kurochkin and Mikhailov 1998?
G. reshetovi Chatterjee, Kurochkin and Mikhailov 1998?
Holotype- (PIN 4492-3) embryo
Comments- Several embryos were described by Elzanowski (1981) and later
referred to Gobipteryx minuta.  Later, Chatterjee, Kurochkin and Mikhailov
described two more embryos as a new neornithine bird, Gobipipus reshetovi.
All of these specimens are described by Kurochkin as enantiornithine
embryos, as the chapter was apparently written before he helped name
Gobipipus.
The embryos described by Elzanowski are enantiornithine, as seen by the
reversed scapulocoracoid articulation.  Kurochkin argues they are not
referrable to Gobipteryx, but this is questionable for two reasons.  First,
the differences noted (larger and more cranially concave naris; sharper
angle between lateral edges of premaxilla; flat, rounded beak) could very
well be  ontogenetic.  Secondly, it is uncertain how much the incorrectly
associated Gobipipus specimens are affecting his opinion.  I would need
access to the original description and the description of Nanantius?
valifanovi to have an educated opinion.
Gobipipus lacks teeth, has subequal metacarpals II and III, one phalanx on
manual digit II and a curved pointed scapula with prominent acromion.  Some
characters (elongate fibula, tibia unfused to astragalocalcaneum, etc.) are
no doubt due to immaturity.  Placing this genus phylogenetically will be
difficult with only embryonic remains available.<<

Good to know, because Chatterjee always puts Gobipteryx in Carinatae at
least...

> Hesperornithiformes fam. et gen. nov.
> The fact these bones are small and highly pneumatized suggests to Kurochin
this species was volant.

Oho! (Sure it is hesperornithiform?)