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Gorgonopsid therapsid clade Rubidgeinae systematics (free pdf)



Ben Creisler
bcreisler@gmail.com

A new paper in PeerJ:

Christian F. Kammerer  (2016)
Systematics of the Rubidgeinae (Therapsida: Gorgonopsia).
PeerJ 4:e1608
doi: https://doi.org/10.7717/peerj.1608
https://peerj.com/articles/1608/



The subfamily Rubidgeinae, containing the largest known African
gorgonopsians, is thoroughly revised. Rubidgeinae is diagnosed by the
absence of a blade-like parasphenoid rostrum and reduction or absence
of the preparietal. Seven rubidgeine species from the Karoo Basin of
South Africa are recognized as valid: Aelurognathus tigriceps,
Clelandina rubidgei, Dinogorgon rubidgei, Leontosaurus vanderhorsti,
Rubidgea atrox, Smilesaurus ferox, and Sycosaurus laticeps.
Rubidgeines are also present in other African basins: A. tigriceps and
S. laticeps occur in the Upper Madumabisa Mudstone Formation of
Zambia, and D. rubidgei, R. atrox, and the endemic species
Ruhuhucerberus haughtoni comb. nov. and Sycosaurus nowaki comb. nov.
occur in the Usili Formation of Tanzania. Aelurognathus nyasaensis
from the Chiweta Beds of Malawi also represents a rubidgeine, but of
uncertain generic referral pending further preparation. No rubidgeine
material is known outside of Africa: the purported Russian rubidgeine
Leogorgon klimovensis is not clearly referable to this group and may
not be diagnosable. Phylogenetic analysis of rubidgeines reveals
strong support for a clade (Rubidgeini) of advanced rubidgeines
including Clelandina, Dinogorgon, Leontosaurus, and Rubidgea. Support
for Smilesaurus as a rubidgeine is weak; it may, as previous authors
have suggested, represent an independent evolution of large body size
from an Arctops-like ancestor. Temporally, rubidgeines are restricted
to the Late Permian, first appearing in the Tropidostoma Assemblage
Zone and reaching highest diversity in the Cistecephalus and
Daptocephalus assemblage zones of the Beaufort Group.