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Fwd: Digalodon (Permain dicynodont) redescribed + Cacops specimen (free pdfs)

Another blocked posting. I'll try again...

---------- Forwarded message ----------
From: Ben Creisler <bcreisler@gmail.com>
Date: Sat, Jan 31, 2015 at 10:15 PM
Subject: Digalodon (Permain dicynodont) redescribed + Cacops specimen
(free pdfs)
To: dinosaur@usc.edu

Ben Creisler

Two recent non-dino papers in open access:

C. F. Kammerer, K. D. Angielczyk, and J. Fröbisch (2015)
Redescription of Digalodon rubidgei, an emydopoid dicynodont
(Therapsida, Anomodontia) from the Late Permian of South Africa.
Fossil Record 18: 43-55

The Late Permian dicynodont Digalodon rubidgei Broom and Robinson,
1948, is redescribed based on reanalysis of the holotype and newly
recognized referable specimens. Digalodon can be diagnosed by the
presence of a long “beak” sharply demarcated from the caniniform
process; an extremely tall zygomatic ramus of the squamosal, with a
thickened, “folded-over” dorsal margin; raised parietal “lips” along
the lateral edges of the pineal foramen; and a broad posterolateral
expansion of the parietal, excluding the postorbital from the back of
the skull roof. Inclusion of Digalodon in a recent analysis of
anomodont phylogeny recovers it as a kistecephalian emydopoid,
specifically as the sister taxon to the clade containing the remaining
kistecephalians. Four definite specimens of Digalodon are known, but
several additional specimens lacking tusks, the swollen pineal “lips”,
and a thickened zygoma may represent sexually dimorphic females or
juveniles. Specimens of Digalodon are restricted to the central
portion of the Karoo Basin, in the area around Graaff-Reinet, and are
part of a characteristic fauna probably representing a limited time


N. B. Fröbisch, A. Brar, and R. R. Reisz (2015)
New specimen of Cacops woehri indicates differences in the ontogenetic
trajectories among cacopine dissorophids.
Fossil Record 18: 73-80

The Lower Permian Dolese locality has produced numerous exquisitely
preserved tetrapod fossils representing members of a lower Permian
upland fauna. Therein, at least nine taxa of the clade Dissorophoidea,
ranging in size from the large predaceous trematopid Acheloma to the
miniaturized amphibamid Doleserpeton, highlight the great taxic and
ecological diversity of this anamniote clade. Here we describe a large
specimen of the dissorophid Cacops woehri, which was previously only
known from the juvenile or subadult holotype skull. Another member of
the genus Cacops present at the Dolese locality, Cacops morrisi, is
also represented by specimens spanning juvenile, subadult, and adult
stages, allowing for a comparison of morphological changes taking
place in the late phases of the ontogenetic trajectory of cacopine
dissorophids. The new find shows that, in contrast to C. morrisi and
C. aspidephorus, C. woehri only undergoes relatively subtle changes in
skull morphology in late ontogeny and retains the overall more gracile
morphology into adult stages. This includes retention of the rather
shallow skull shape as well as a pattern of sculpturing consisting of
elongate ridges and grooves and a large occipital flange. This
suggests somewhat different functional demands in C. woehri than in
other known species of Cacops, possibly associated with a different
ecology paralleling the great taxic diversity of dissorophoids at the
Dolese locality.