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Re: Bunostegos (Permian pareiasaur from Africa) skull described (news release)



Here's the official paper in open-access:

Linda A. Tsuji, Christian A. Sidor, J.- Sébastien Steyer, Roger M. H.
Smith, Neil J. Tabor & Oumarou Ide (2013)
The vertebrate fauna of the Upper Permian of Niger—VII. Cranial
anatomy and relationships of Bunostegos akokanensis (Pareiasauria).
Journal of Vertebrate Paleontology 33(4): 747-763
DOI:10.1080/02724634.2013.739537
http://www.tandfonline.com/doi/full/10.1080/02724634.2013.739537#.UcnlvPm1FcQ

We describe newly recovered cranial material of Bunostegos
akokanensis, a pareiasaurian reptile known from the Upper Permian
Moradi Formation of northern Niger. Bunostegos is highly
autapomorphic, with diagnostic cranial features including two or three
hemispherical bosses located above and between the external nares;
laterally projecting supraorbital ‘horn’ formed by an enlarged
postfrontal; large foramen present on ventral surface of postfrontal;
and hemispherical supratemporal boss located at posterolateral corner
of skull roof. We addressed the phylogenetic position of Bunostegos by
incorporating it into a cladistic analysis of 29 parareptilian taxa
(including all 21 currently valid pareiasaurs) and 127 cranial and
postcranial characters. The results of this analysis place Bunostegos
as more derived than middle Permian forms such as Bradysaurus and as
the sister taxon to the clade including Deltavjatia plus Velosauria.
Certain characters, such as the pattern of cranial ornamentation and
the size and placement of the tabulars, appear to be more similar to
more derived pareiasaurs such as Elginia from Scotland and Arganaceras
from Morocco, but the most parsimonious tree topology indicates that
these features were evolved independently in the Nigerien form. The
lack of both dicynodont herbivores and Glossopteris, combined with the
presence of a giant herbivorous captorhinid, indicates a markedly
different community structure in the Permian of Niger compared with
those for contemporaneous southern Pangean basins (i.e., Karoo,
Luangwa, Ruhuhu). The endemic tetrapod fauna of Niger supports the
theory that central Pangea was biogeographically isolated from the
rest of the supercontinent by desert-like conditions during Late
Permian times.

On Mon, Jun 24, 2013 at 12:49 PM, Ben Creisler <bcreisler@gmail.com> wrote:
> From: Ben Creisler
> bcreisler@gmail.com
>
>
>
> The free paper is not yet available on the JVP website, but the news
> release is out for those interested:
>
> http://phys.org/news/2013-06-bumpy-beast-dweller.html