EVOLUTIONARY TRENDS IN TRIASSIC DICYNODONTIA

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dc.contributor.author Keyser, A. W.
dc.date.accessioned 2014-12-19T12:51:30Z
dc.date.available 2014-12-19T12:51:30Z
dc.date.issued 1974
dc.identifier.issn 0078-8554
dc.identifier.uri http://hdl.handle.net/10539/16049
dc.description.abstract Triassic Dicynodontia differ from most of their Permian ancestors in a number of specialisations that reach extremes in the Upper Triassic. These are ( 1) increase in total body size, (2) increase in the relative length of the snout and secondary palate by backward growth of the premaxilla, (3) reduction in the length of the fenestra medio-palatinalis combined with posterior migration out of the choanal depression, (4) shortening and dorsal expansion of the intertemporal region, (5 ) fusion of elements in the front part of the brain-case, (6) posterior migration of the reflected lamina of the mandible, (7) disappearance of the quadrate foramen and the development of a process of the quadrate that extends along the quadrate ramus of the pterygoid. It is thought that the occurrence of the last feature in Dinodontosaurus platygnathw Cox and Jacheleria colorata Bonaparte warrants the transfer of the species platygnathus to the genus Jacheleria and the erection of a new subfamily, Jachelerinae nov. It is concluded that the specialisations of the Triassic forms can be attributed to adaptation to a Dicroidium-dominated flora. en_ZA
dc.language.iso en en_ZA
dc.title EVOLUTIONARY TRENDS IN TRIASSIC DICYNODONTIA en_ZA
dc.type Article en_ZA


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