On the Structure of the Skull in the Mammal-Like Reptiles of the Suborder Therocephalia

  title={On the Structure of the Skull in the Mammal-Like Reptiles of the Suborder Therocephalia},
  author={Robert . Broom},
  journal={Philosophical Transactions of the Royal Society B},
  • R. Broom
  • Published 3 March 1936
  • Biology
  • Philosophical Transactions of the Royal Society B
The first-known mammal-like reptiles were discovered by Andrew Geddes Bain (1845) in the Karroo Beds of South Africa about a hundred years ago. The large majority of the species he discovered belong to the Anomodont group, of which Dicynodon is the best-known genus—characterized by having a tortoise-like beak with or without permanent-growing, large, upper canines. Carnivorous types are very much rarer than the vegetarian Anomodonts, and Bain was successful in getting only comparatively few… 
Tooth replacement in mammal-like reptiles of the suborders gorgonopsia and therocephalia
  • K. Kermack
  • Biology, Medicine
    Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
  • 1956
An investigation of two groups of the more primitive therapsids, the Gorgonopsia and the Therocephalia, which lie close to the main line of synapsid evolution, finds that after a certain time in the animal’s life tooth replacement ceased, the permanent upper canines being always borne by the anterior alveoli.
A review of Robert Broom’s therapsid holotypes: have they survived the test of time?
Robert Broom established the monophyletic origin of the mammals, thereby rebutting the then prevailing theory that the most important living class had been polyphyletically derived from a diverse range of reptiles and amphibians.
Whaitsiid Therocephalia and the origin of cynodonts
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.
New features of the snout and orbit of a therocephalian therapsid from South Africa
The anterior part of the externally poorly preserved skull of a therocephalian from the Karoo Basin in South Africa is described, using the method of serial grinding, and an anteriorly positioned sinus, situated directly behind the canine root, is homologized with the maxillary sinus of gorgonopsians.
On the Functional Morphology of the Gorgonopsid Skull
It is proposed that the carnivorous therapsids should be classified into two equal ranks, the Gorgonopsia and the Theriodonta and that they were probably derived separately from the sphenacodont pelycosaurs.
New Late Permian Therocephalian
The well-preserved, acid-prepared skull of Moschowhaitsia vjuschkovi reveals a number of features unexpected in a theriodont of otherwise generally primitive aspect.
The Evolution of Mammalian Sight and Hearing
The Middle Jurassic gives glimpses of the evolving mammals. From recent discoveries (see Chapter 7 for details) there is evidence of a much wider range of mammalian life than was seen in the Upper
On the cranial anatomy of some gorgonopsids and the synapsid middle ear.
It is concluded that the deflected articular process present among synapsid reptiles generally was a true retroarticular process, giving attachment to a depressor mandibuli muscle, and that its ventral deflection was a modification to permit the wide gape necessary in forms having large canine teeth.
The hyomandibular of Eusthenopteron and the tetrapod middle ear
  • T. S. Westoll
  • Medicine
    Proceedings of the Royal Society of London. Series B - Biological Sciences
  • 1943
It is considered that Eaton’s theory of the transformation of the Rhipidistian hyomandibular to the primitive tetrapod ‘stapes’ or columella is essentially correct.
Middle ear structures in the Permian Glanosuchus sp. (Therocephalia, Therapsida), based on thin sections
It is shown that the reflected lamina of Glanosuchus is in major parts an extremely thin bony plate, which is best interpreted as a sound-receiving element overlying an air-filled recessus of the pharynx.