Re: NEW NEORNITHINE & PTEROSAUR STUFF

["Jaime A. Headden" <qilongia@yahoo.com>]

Darren Naish (darren.naish@port.ac.uk) wrote:

<Mayr, D. & Daniels, M. 2001. A new short-legged landbird from the early Eocene 
of Wyoming and
contemporaneous European sites. _Acta Palaeontologica Polonica_ 46, 393-402.

  The strange new taxon _Fluvioviridavis platyrhamphus_ ('broad billed Green 
River bird') -
previously referred to the ?steatornithid _Prefica_ (see comments on identity 
of this taxon in
Cracraft's recent paper on southern neornithine origins) and figured in 
Feduccia (1996) as a 
possible roller-like caprimulgiform - is here described and discussed. The type 
specimen (complete
skeleton) is from the Green River Fm, but referable material is from Messel and 
the London Clay.
_Fluvioviridavis_ lacks derived characters that allow it to be convincingly 
allocated to a
neornithine clade. Its short tarsomet and expanded proximal humerus suggest 
comparisons with
caprimulgiforms but it has an alular claw and cup-like scapular facet on the 
coracoid, indicating
that it is basal within the 'higher landbird' assemblage. Long wings and 
tyrannid-like bill
suggest an aerial, insectivorous mode of life.>

  More than that, Darren, that taxon and one Mayr described last year,

  Mayr, G. 2000. A new raptor-like bird from the Lower Eocene of North America 
and Europe.
_Seckenbergiana lethea_ 80 (1): 59-65,

  *Tynskya eocaena* both have claws. *Fluvioviridiornis* and *Tynskya* both 
have an alular claw,
and the former also possesses a major digit claw, all very small relative to 
manus, and may not
have been evident under a cursorial examination. *Tynskya* appears to be a 
raptorial bird with
affinities to the Psuedasturidae, and appears to be related to birds from the 
Messel that Feduccia
(1996) labeled as owls. It otherwise has similarities to strigiforms and 
falconiforms ... the
postcrania is generally standardized, but has a zygodactyl pes, but no true 
Sehnenhalter. The
skull is relatively short and owl-like. *Tynskya* hails from the Tynksy Quarry 
of Wyoming, and
referred material comes from Messel. This adds to the Eocene pan-Laurasian 
birds.

  However, and more relevant to the list's interests, are the claws. Mayr 
suggests that these may
have been prevalent throughout basal neornithine diversification. I have a 
question: to what use
can such claws be of, and be prevalent. They are present among many extant 
birds, including the
hoatzin ... but for what function can they serve to have _not_ been 
vestigialized in all birds? It
is obvious that hoatzins use them for locomotion, but it is not clear to what 
use they serve in
other taxa. So it is a matter of an enigma: what _would_ such small claws 
serve? And yes, we know
_all_ about scampering young hoatzins...


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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