Dental Occlusion in a 260-Million-Year-Old Therapsid with Saber Canines from the Permian of Brazil

  title={Dental Occlusion in a 260-Million-Year-Old Therapsid with Saber Canines from the Permian of Brazil},
  author={Juan Carlos Cisneros and Fernando Abdala and Bruce S. Rubidge and Paula Dentzien-Dias and Ana de Oliveira Bueno},
  pages={1603 - 1605}
Tiarajudens extends the date of dental occlusion and suggests why the members of this Permian group were such diverse and successful herbivores. Anomodonts, a group of herbivorous therapsid “mammal-like reptiles,” were the most abundant tetrapods of the Permian. We present a basal anomodont from South America, a new taxon that has transversally expanded palatal teeth and long saber canines. The function of the saber teeth is unknown, but probable uses include deterring attack from predators and… 
On Dental Occlusion and Saber Teeth
A new therapsid fossil from South America is described, Tiarajudens eccentricus, which displays a unique dentition, including broad chewing teeth on the palate and a pair of extremely long saber canines, which provides novel insights into early tooth differentiation in synapsids and into the evolution of herbivory (plant eating) and its accompanying complex social interactions.
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The outsized, blade-like caniniforms of the herbivorous Tiarajudens allow several non-exclusive ecological interpretations, among which the authors favour intraspecific display or combat.
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The evolution of an ever-growing dentition, such as a tusk, is predicated on the evolution of significantly reduced tooth replacement and a permanent soft-tissue attachment, which helps to explain why tusks are restricted to this clade among extant vertebrates.
The Brazilian Pareiasaur Revisited
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The basal position of Anomocephalus, together with its South African occurrence, strongly supports the postulate that a Gondwanan distribution was ancestral for anomodonts.
The Functional Anatomy of a Permian Dicynodont
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New Basal Synapsid Supports Laurasian Origin for Therapsids
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The origin and early radiation of the therapsid mammal‐like reptiles: a palaeobiological hypothesis
  • T. Kemp
  • Biology, Medicine
    Journal of evolutionary biology
  • 2006
An hypothesis is presented in which the origin of the therapsids resulted from a correlated progression of character evolution leading to higher levels of metabolic activity and homeostatic regulation of the body.
Pareiasaurids from the Rio do Rasto Formation, Southern Brazil: biostratigraphic implications for Permian faunas of the Paraná Basin
Comparison between pareiasaurid materials from Aceguá, originally assigned to Pareiasaurus americanus, and a new cranium from Posto Queimado indicates that they belong to the same taxon. Despite
The Permian mammal-like herbivore Diictodon, the oldest known example of sexually dimorphic armament
This earliest well–documented example of dimorphic armament suggests that sexual dimorphism, and the complex social behaviour that accompanies it, have long been characteristic of the synapsid lineage.
Earliest evidence for efficient oral processing in a terrestrial herbivore
It is proposed that the capacity to comminute tough plant foods was critical to the diversification of anomodonts, the most diverse, widely dispersed and abundant group of Palaeozoic terrestrial vertebrates, and to the onset of modern terrestrial ecosystems.
A review of fighting adaptations in dinocephalians (Reptilia, Therapsida)
The cranial structure of anteosaurid and many tapinocephalid dinocephalians came modified in a manner consistent with Geist's hypothesis that they used their heads for pushing and ramming during intraspecific combat, indicating that the head was reoriented into a position suitable for butting.