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Re: [dinosaur] Confuciusornis cranial morphology



All very good points - my only caution is that many wing shape reconstructions 
assume that Confuciusornis has slotted wingtips, which it likely did not 
(probably could not use them for structural reasons). So the anatomical aspect 
ratio and functional aspect ratio were likely the same in Confuciusornis, and 
consequently, the effective aspect ratio would be lower than for living birds 
with slotted wings and a comparable anatomical aspect ratio. Confuciusornis 
might have compensated with a higher anatomical AR than living forest birds.

Cheers,

âMike Habib

Sent from my Cybernetic Symbiote

> On Apr 9, 2018, at 10:07 PM, Tim Williams <tijawi@gmail.com> wrote:
> 
> Sally-striking foraging behavior fits with the aspect ratio of
> _Confuciusornis_ wings.  Wide, broad wings confer high maneuverability
> (Falk et al. 2016 doi.org/10.1371/journal.pone.0167284), which would
> be essential for snatching flying insects out of the air.  As
> Elzanowski &c note, sally-strikes could be launched from either the
> ground or an arboreal perch.  However, contra Elzanowski &c, it would
> not have been necessary for _Confuciusornis_ to climb trees in order
> to reach a perch, given the likelihood that it could take off from the
> ground (e.g. Dececchi & Larsson 2011
> doi:10.1371/journal.pone.0022292).  In any case, the manus of
> _Confuciusornis_ was highly unsuitable for tree-climbing (e.g., Peters
> & Ji 1999 J.Ornithol. 140:41-50; Chiappe et al. 1999 Bull. AMNH
> 242:1-89, etc).
> 
>> On Tue, Apr 10, 2018 at 7:36 AM, Ben Creisler <bcreisler@gmail.com> wrote:
>> 
>> 
>> 
>> Ben Creisler
>> bcreisler@gmail.com
>> 
>> A new paper:
>> 
>> 
>> 
>> Andrzej Elzanowski, D. Stefan Peters & Gerald Mayr (2018)
>> Cranial morphology of the Early Cretaceous bird Confuciusornis.
>> Journal of Vertebrate Paleontology Article: e1439832
>> DOI: 10.1080/02724634.2018.1439832.
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tandfonline.com_doi_full_10.1080_02724634.2018.1439832&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=0GAJyNuAp8oHra3hqdHqNpJl8L-7SHAgb_DTdw9v5eo&s=AgQvJi_TyDDRlkUSyT-CPiQJURTlGMxaBkGFiwk0UbU&e=
>> 
>> 
>> Confuciusornis sanctus has been heralded as a bird with an ancestrally
>> diapsid skull, although this does not match its phylogenetic position as
>> determined by other skeletal features. Based on 13 cranial specimens in
>> European collections, we demonstrate that the observed scaffolding in the
>> temporal region is highly derived and comparable to some of 21â23 cases of
>> secondary bridges across the temporal fossa that evolved in modern birds. In
>> Confuciusornis, the temporal fossa is crossed by a secondary temporal bar
>> (absent in Eoconfuciusornis) that is continuous with the braincase but
>> discontinuous with the postorbital process. A small postorbital bone (if
>> present) is covered by this secondary ossification. The postorbital process
>> is continuous with a prominent supraorbital rim and extends to the jugal as
>> in sally-striking birds, including some Podargidae (Podargus), Leptosomidae,
>> Brachypteraciidae, Coraciidae, Bucconidae, and Galbulidae, which tend to
>> have wide gapes, large jaws with deep cranial rostra (and the nasal opening
>> in a caudal position), and require additional attachments of musculus
>> adductor mandibulae externus for fast and powerful snatching of the prey.
>> The best modern analogue for the secondary temporal scaffolding seen in
>> Confuciusornis is provided by Podargus, in which the long postorbital
>> process is propped up by the temporal bar in addition the secondary bridge
>> across the temporal fossa. The cranial evidence identifies Confuciusornis
>> sanctus as a sally-striking predator.
>> 
>> 
>> ================
>> 
>> 
>> 
>>