Re: External mandibular fenestra in basal pterosaurs

[Tim Williams <tijawi@gmail.com>]

Although this study is principally concerned with the phylogenetic
position of pterosaurs, it also discusses the non-pterosaurian taxa
_Tawa_ and _Dromomeron_.  According to Bennett:

* _Dromomeron romeri_ and _Tawa hallae_ are conspecific, with the
femora representing an ontogenetic series.  (The apparent absence of a
fourth trochanter in the _Dromomeron romeri_ holotype is attributed to
both its juvenile age and crushing.)  This taxon is a theropod.

* _Dromomeron gregorii_ is a small basal dinosauriform, and is not
congeneric with _Dromomeron romeri_.




On Wed, Jul 8, 2015 at 1:23 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
>
> A new paper:
>
> S. Christopher Bennett (2015)
> An external mandibular fenestra and other archosauriform characters in
> basal pterosaurs re-examined.
> Historical Biology 27(6): 796-814
> DOI:10.1080/08912963.2015.1036257
> http://www.tandfonline.com/doi/full/10.1080/08912963.2015.1036257#abstract
>
> It was claimed that pterosaurs had external mandibular fenestrae,
> antorbital fossae and muscle scars homologous with the femoral fourth
> trochanter of archosauriforms, and that those characters suggested
> that the Pterosauria were within the clade Erythrosuchus +
> Archosauria. Pertinent parts of available specimens are described to
> confirm that one pterosaur had external mandibular fenestrae and one
> had antorbital fossae. However, arguments are presented that
> possession of external mandibular fenestrae does not support inclusion
> of the Pterosauria within the clade Erythrosuchus + Archosauria and
> that the antorbital fossae in the one pterosaur are not homologous
> with those of the clade Erythrosuchus + Archosauria. Arguments are
> also presented that the possession of a m. caudofemoralis scar by some
> pterosaurs does not support inclusion of the Pterosauria within the
> clade Erythrosuchus + Archosauria, whereas the lack of homologous
> antorbital fossae and a mound-like or aliform fourth trochanter
> supports exclusion of the Pterosauria from that clade.