Temnospondyli | Anapsida | Therapsida
During this period the low diversity Caseid fauna is supplanted (and for the most part replaced) by a rich range of early therapsids (mammal-like reptiles or parammals) (Fig. 2, faunal stage 1). It is not unlikely that these early therapsids may have had the beginnings of metabolic devolpment towards the mammalian condition, but I cannot agree with Dr Bakker that they were already partially or fully endothermic. In any case, these animals quickly radiated into an extraordinary variety of large and small terrestrial herbivores and camivores. The Early Permian ectothermic families died out early during, or perhaps prior to, this time.
A high large herbivore diversity is indicated by the floodplain facies of the Tapinocephalus Zone of the South African Karroo, five families or subfamilies and six genera are rather widespread and common; biomass D is about four. This high level of large herbivore diversity was to be also achieved by the radiations of the succeeding therapsid, therapsid-archosaur, dinosaur, and mammal empires. Each dynasty seems to have ended with a mass extinction, and, following a low diversity period, a new ecological community evolves.
During this time, all the big herbivores and carnivores were great lumbering creatures; some of which may have been semi-aquatic, while others were fully terrestrial. Most were of the Dinocephalian type. These were impressive-looking beasts easily recognised by their distinctive dentition of intermeshing incisors. Many attained weights of a tonne or more, and lengths of 3 to 6 meters. The only other animals of comparable size were the Pareiasaurs, armoured herbivores specialised for a semi-aquatic existence, and possessing a truely bizarre cranial ornamentation. Accompanying these strange giants were a variety of smaller therapsids and lizard-like Anapsids.
The following map by Anderson and Cruikshank give the known distribution of Tapinocephalus age faunas. This refers only to the location of fossil remains. The actual distribution would naturally have been much wider.
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some Links and References |  |
J. M. Anderson & A. R. I. Cruikshank, "The Biostratigraphy of the Permian and Triassic, Part 5, a review of the classification and distribution of Permo-Triassic Tetrapods," in Paleontologica Africana, 21, 15-44 (1978)
R.T. Bakker, 1975 "Dinosaur Renaissance", Scientific American April 1975
R.T. Bakker, 1977 "Tetrapod Mass Extinctions - A model of the regulation of speciation rates and immigration by cycles of topographic diversity" in A. Hallam, ed. Patterns of Evolution as illustrated by the Fossil Record, Elsevier Scientific Publishing Company, Amsterdam, Oxford, New York, pp.439-68
Michael A. Cluver, 1978, Fossil Reptiles of the South African Karoo, South African Museum, Cape Town
Professor Paul Eric Olsen, Tetrapods
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Temnospondyli | Anapsida | Therapsida
