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Re: [dinosaur] Triopticus, new dome-headed stem archosaur from Late Triassic of Texas (free pdf)



The convergence between Triassic archosauromorphs and post-Triassic
dinosaurs is definitely striking: shuvosaurids and
elaphrosaurines/ornithomimids; aetosaurs and ankylosaurs; _Triopticus_
and pachycephalosaurs; and so on.  Another possible example of
convergence is _Protoavis_ and paravians.  I certainly don't mean to
suggest that the _Protoavis_ hypodigm comes from a bird-like biped
that could fly around and perch in trees.  I'm referring only to the
braincase, which seems very 'advanced' for the Late Triassic.  In many
respects the _Protoavis_ braincase is very similar to that of
troodontids (though perhaps not to the degree suggested by Chatterjee,
1991).  This has been noted previously (e.g., Currie & Zhao, 1993;
Paul, 1991 - in DA).  Whatever the _Protoavis_ braincase actually
belongs to, this creature might represent a small and relatively
'large-brained' archosauromorph that was convergent on Cretaceous
paravians.


On Wed, Oct 12, 2016 at 10:18 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> A commentary:
>
>
> Michael J. Benton (2016)
> Palaeontology: Dinosaurs, Boneheads and Recovery from Extinction.
> Current Biology 26(19): R887-R889
> doi: 
> https://urldefense.proofpoint.com/v2/url?u=http-3A__dx.doi.org_10.1016_j.cub.2016.07.029&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=rDvfekKdUDGvuGzZ5DV3IuqnyelvC0-KKNbI_nFocW4&e=
>  
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.cell.com_current-2Dbiology_fulltext_S0960-2D9822-2816-2930780-2D1&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=0BdX8ekDTlMngPZ4kQybsgNR-9BruDIwWQbSFAyHt5A&e=
>  
> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.sciencedirect.com_science_article_pii_S0960982216307801&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=5FSkgmbdtOd7f4VnFsFBA_RXa2S3RiaJ6t7o-0YA0Sc&e=
>  
>
> The Triassic was a time of turmoil, as life recovered from
> near-annihilation. Archosauromorph reptiles flourished and diversified as
> they filled empty ecological niches, and some of them presaged later
> dinosaurian inventions, such as thickened skull roofs.
>
> NOT YET POSTED on Benton's pdf reprint site:
>
> https://urldefense.proofpoint.com/v2/url?u=http-3A__palaeo.gly.bris.ac.uk_benton_reprints_&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=6-98TTnhOfOH8cINRPuPZ2nkDOYt23orZC1-HzAbbIw&e=
>  
>
>
> On Thu, Sep 22, 2016 at 9:17 AM, Ben Creisler <bcreisler@gmail.com> wrote:
>>
>>
>> Ben Creisler
>> bcreisler@gmail.com
>>
>>
>> A new paper:
>>
>> Michelle R. Stocker, Sterling J. Nesbitt, Katharine E. Criswell, William
>> G. Parker, Lawrence M. Witmer, Timothy B. Rowe, Ryan Ridgely & Matthew A.
>> Brown (2016)
>> A Dome-Headed Stem Archosaur Exemplifies Convergence among Dinosaurs and
>> Their Distant Relatives.
>> Current Biology (advance online publication)
>> DOI: 
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__dx.doi.org_10.1016_j.cub.2016.07.066&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=wsXOOropOzJF0TpT1PavFKqw4W187fHDtqrPIPwHr3w&e=
>>  
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.cell.com_current-2Dbiology_fulltext_S0960-2D9822-2816-2930860-2D0&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=IH-o0QRW8pAnk7AlNco6xsl5gJiRCGihA4iLldJUibk&e=
>>  
>>
>>
>> pdf:
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.cell.com_current-2Dbiology_pdf_S0960-2D9822-2816-2930860-2D0.pdf&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=c99F8ZrdfJiXQ-pe1QqPPAE7fGq8iSlsPQ5pnc1v8lw&e=
>>  
>>
>>
>> Following the end-Permian extinctions, crown-group reptiles underwent an
>> extensive diversification. From this radiation, archosauromorphs (reptiles
>> closer to birds and crocodylians than to squamates) preserve one of the most
>> diverse and disparate fossil records within Reptilia. The oldest and
>> best-documented terrestrial record of this archosauromorph diversification
>> in North America is the Late Triassic Otis Chalk assemblage. This assemblage
>> includes an exceptional range of disparate cranial morphologies, dental
>> modifications, and overall bauplans. Common clades in this assemblage are
>> phytosaurs, with hyper-elongated and narrow rostra that have invoked
>> statements of convergence with extant crocodylians, and armored aetosaurs,
>> resembling the Cretaceous tank-like ankylosaurian dinosaurs. Reevaluation of
>> the Otis Chalk assemblage (Supplemental Information) has illuminated further
>> examples of convergent morphology, such as a shuvosaurid similar to Effigia
>> that mimics the ornithomimid “ostrich-dinosaurs”. Exemplifying this extreme
>> morphological convergence, we present here a new dome-headed taxon from the
>> assemblage, which further illustrates the extraordinary range of
>> morphological disparity present early in the Late Triassic.
>>
>>
>>
>> ===
>>
>>
>>
>> News:
>>
>>
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__phys.org_news_2016-2D09-2Dbizarre-2Dspecies-2Dextinct-2Dreptile-2Ddinosaurs.html&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=cs913lXTDF-STaVcsHVUj1Hx_uvrLdB-uG_I6DzUVns&e=
>>  
>>
>>
>>
>> https://urldefense.proofpoint.com/v2/url?u=http-3A__www.smithsonianmag.com_science-2Dnature_paleontologists-2Dpuzzle-2Dover-2Dfirst-2Dbonehead-2D180960543_&d=DQIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=3r8OKZMNh8uUOHoMGx5KY2K1JJZT-OPkrIAhNtg60_4&s=DcIt1YapHt3650-DJXPRqvAgeT-3-AF488wzLMFgUN4&e=
>>  
>>
>>
>>
>