Re: [dinosaur] Mengciusornis, new toothed ornithuromorph from Early Cretaceous of China

[Tim Williams <tijawi@gmail.com>]

The etymology of _Mengciusornis_ is stated as: "The name is dedicated
to the ancient Chinese philosopher Mengzi; plus âornisâ for bird
(Greek)."

The genus _Mengciusornis_ would appear to follow the naming convention
set by _Confuciusornis_.  Mencius (or Mengcius or Mengzi) was a
Confucian philosopher, second only to Confucius (Kongfuzi) himself
(according to those well-versed in ancient Chinese philosophers, which
I'm not).

The recovery of a _Bellulornis_(_Apsaravis_-_Patagopteryx_-_Vorona_)
clade, as sister taxon to the new clade Schizoouridae, is intriguing.
Although I don't intend to read too much into this, I'm curious what
pulls these four rather disparate taxa together.  _Apsaravis_ has
previously been linked to _Palintropus_ and maybe _Ambiortus_.
_Patagopteryx_, as everyone knows, was secondarily flightless.




On Tue, Nov 12, 2019 at 6:43 AM Ben Creisler <bcreisler@gmail.com> wrote:
>
>
> Ben Creisler
> bcreisler@gmail.com
>
> A new paper:
>
>
> Mengciusornis dentatus gen. et sp. nov.
>
> Min Wang, Jingmai K. OâConnor, Shuang Zhou & Zhonghe Zhou (2019)
> New toothed Early Cretaceous ornithuromorph bird reveals intraclade diversity 
> in pattern of tooth loss.
> Journal of Systematic Palaeontology  (advance online publication)
> doi: 
> https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1080_14772019.2019.1682696&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=X7aTFSudhr2Ir4N49R3iIs2Ms3l2ycgI7vpOHSqgnG4&s=8fSna4ufmbtXYsNUdhAfMHqVEBNAftWCE55NTbCxrdQ&e=
>  
> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tandfonline.com_doi_abs_10.1080_14772019.2019.1682696&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=X7aTFSudhr2Ir4N49R3iIs2Ms3l2ycgI7vpOHSqgnG4&s=TrpBq39fyIcJE9RioiP-DwqWEOElRbFBlXi-TVUAxgU&e=
>  
>
>
> The earliest record of the Ornithuromorpha, which includes crown birds, is 
> currently known from the Early Cretaceous Jehol Biota in north-eastern China. 
> Here we describe a new ornithuromorph bird, Mengciusornis dentatus gen. et 
> sp. nov., from the Jiufotang Formation of this biota. Mengciusornis preserves 
> a suite of morphological features exclusively observed among ornithuromorphs 
> in the sympatric taxon Schizooura, including a robust and âVâ-shaped 
> furcula with a short hypocleidium, and a humerus with a large, rectangular 
> deltopectoral crest in which the distodorsal corner is distinctively 
> developed into a sharp, angular point. The results of our phylogenetic 
> analysis recover these two species together in a clade, positioned stemward 
> within the Ornithuromorpha. Mengciusornis has toothed premaxillae, in stark 
> contrast with the edentulous jaws of Schizooura, demonstrating that dentition 
> varied considerably between some closely related species. Furthermore, all 
> previously known Jehol ornithuromorphs with toothed premaxillae have an 
> edentulous rostral portion of the element, suggesting that tooth loss in this 
> clade proceeded from the rostral end caudally, whereas in Mengciusornis the 
> premaxilla lacks this edentulous rostral tip although the maxilla and dentary 
> are toothless, indicating that the pattern of tooth loss, not unexpectedly, 
> varied between lineages of ornithuromorphs. This observation suggests a 
> strong degree of plasticity in the developmental mechanisms regulating tooth 
> and beak formation, which is supported by earlier evidence that indicates 
> teeth have been lost multiple times within Aves and Dinosauria. Mengciusornis 
> preserves a ventrally hooked scapular acromion that is convergently evolved 
> in parallel with some enantiornithines and neornithines, providing further 
> evidence of the homoplasy that characterizes avian evolution.