. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE EARLY THERAPSIDS 43 cachet fully developed in one bound and wholly sterile. It is of interest to note that the gorgonopsians, apparently of Cisuralian origin, have only three genera in the Russian Upper Permian. Inostrancevia is a giant gorgonopsian, whereas the aberrant Proburnetia is very similar to Burnetia of the Karoo. The Dicynodontia, with two families in the Middle Permian, numeri- cally rich in individuals, formed a significant element in the fauna as the sole assemblage of small herbivo
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. THE EARLY THERAPSIDS 43 cachet fully developed in one bound and wholly sterile. It is of interest to note that the gorgonopsians, apparently of Cisuralian origin, have only three genera in the Russian Upper Permian. Inostrancevia is a giant gorgonopsian, whereas the aberrant Proburnetia is very similar to Burnetia of the Karoo. The Dicynodontia, with two families in the Middle Permian, numeri- cally rich in individuals, formed a significant element in the fauna as the sole assemblage of small herbivores preyed on by the smaller to medium sized carnivores of those times. With a fully developed morphological pattern from the base of the Middle Permian they waxed exceedingly until becoming extinct in the Middle Trias. The basic pattern, fully developed at the beginning of the Middle Permian, remains unchanged during their long span of life. But in the Upper Permian a mass of small variations occur as witnessed by the fact that over 200 species have been named. During these times the dicynodonts were extremely abundant, by far outnumbering all their contemporary therapsids and constitute the bulk of the herbivores on which the gorgonopsians preyed. In the Lower Trias the lystrosaurs were very nearly the only herbivores preyed on by some small cynodonts and the predaceous Chasmatosaurus. In Cynognathus zone times we get the kannemeyerids forming the end of this line of development, which during its long span of life continued basically unchanged and sterile. The Dicynodontia, with the Cisuralian form Otsheria as starting point, had but five descendant genera in Russia, but since the Upper Permian have spread to Scotland, China, Indo-China, North and South America, India and Antarctica. Thus, notwithstanding their innate inability to escape from their con- fining basic structural pattern they were very adaptable herbivorous reptiles, well able to fit into all the vicissitudes of
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
