Reassessment of the Morphology and Paleobiology of the Therocephalian Tetracynodon Darti (Therapsida), And The Phylogenetic Relationships of Baurioidea

@inproceedings{Sigurdsen2012ReassessmentOT,
  title={Reassessment of the Morphology and Paleobiology of the Therocephalian Tetracynodon Darti (Therapsida), And The Phylogenetic Relationships of Baurioidea},
  author={Trond Sigurdsen and Adam K. Huttenlocker and Sean P. Modesto and Timothy Rowe and Ross J. Damiani},
  year={2012}
}
ABSTRACT Several new specimens of the Triassic therocephalian Tetracynodon darti have become available in recent years, allowing substantial corrections and expansions to previous descriptions. We here analyze T. darti in the context of therocephalian relationships and biology, using computed tomographic (CT) scanning to reveal details of the skull. Histological sections, as well as the degree of ossification of individual elements, both suggest that the available specimens are subadults… 
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References

SHOWING 1-10 OF 218 REFERENCES
The skeleton of a baurioid therocephalian therapsid from the Lower Triassic (Lystrosaurus Zone) of South Africa
TLDR
The first full reconstruction of a baurioid (“scaloposaur”) therocephalian is given, showing that these therapsids were very mammal-like in their proportions, with relatively long limbs, attenuated lumbar ribs, and a highly reduced tail.
A New Specimen of Promoschorhynchus (Therapsida: Therocephalia: Akidnognathidae) from the Lower Triassic of South Africa and its Implications for Theriodont Survivorship Across the Permo-Triassic Boundary
ABSTRACT The anatomy of a new subadult specimen of eutherocephalian therapsid, attributed to Promoschorhynchus cf. P. platyrhinus, is described from lowermost Triassic Lystrosaurus Assemblage Zone
A SECOND SPECIMEN OF LEMUROSAURUS PRICEI (THERAPSIDA: BURNETIAMORPHA)
TLDR
A cladistic analysis of 10 therapsids, two outgroups, and 38 characters indicates that Lemurosaurus is the sister taxon to a clade including Bullacephalus, Proburnetia, and Burnetia and that it is most parsimonious to infer that burnetiamorphs originated in southern Africa.
Whaitsiid Therocephalia and the origin of cynodonts
TLDR
It is argued that the organization of the cynodont skull can be seen as a logical functional development from the more primitive condition, and in particular, the streptostylic nature of the jaw articulation, the enlargement of the dentary and reduction of the postdentary bones, may all be correlated with the development of a masseter muscle.
Taxonomic Revision of Therocephalians (Therapsida: Theriodontia) from the Lower Triassic of Antarctica
TLDR
The results of the taxonomic revision indicate that the therocephalian fauna of Antarctica lacks endemic genera and thus corresponds to that of the Triassic Lystrosaurus Assemblage Zone fauna, which is considered to sample a broadly distributed Lower Triassic tetrapod fauna.
The Endocranial Cavity of a Nonmammalian Eucynodont, Chiniquodon theotenicus, and Its Implications for the Origin of the Mammalian Brain
ABSTRACT The braincase and endocranial cavity of a specimen of a nonmammalian eucynodont Chiniquodon is described and illustrated, and a tentative reconstruction of the gross anatomy of the brain
An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida)
TLDR
The analysis supports the hypothesis that Therocephalia represents the monophyletic sister taxon to Cynodontia, with as many as 15 morphological synapomorphies, in contrast with other recent analyses of lesser taxon sampling.
A new skeleton of the therocephalian synapsid Olivierosuchus parringtoni from the Lower Triassic South African Karoo Basin
Abstract:  We provide a redescription of the therocephalian therapsid Olivierosuchus parringtoni based on a new specimen recovered from the Lower Triassic Lystrosaurus Assemblage Zone of South Africa
The most basal anomodont therapsid and the primacy of Gondwana in the evolution of the anomodonts
TLDR
The basal position of Anomocephalus, together with its South African occurrence, strongly supports the postulate that a Gondwanan distribution was ancestral for anomodonts.
The Primitive Cynodont Procynosuchus: Functional Anatomy of the Skull and Relationships
TLDR
The anatomy of the internal nares indicates that an arrangement of Jacobson’s organ and associated nerves, blood vessels and glands comparable to that of monotremes was present and an attempt is made to interpret its anatomy in functional terms.
...
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