Chapter 30 Mammalia

Introduction. The classification employed here and the order of taxa listed are essentially those given by Simpson (1945). The only additions are the subclass Eotheria and the following orders of Metatheria: Marsupicarnivora, Paucituberculate, Peramelina and Diprotodonta, and of Eutheria: Deltatheridia, Trigonostylopoidea, Xenungulata and Desmostylia. The only serious problem encountered in compiling the documentation was with the early and hence more primitive members of certain orders. Thus the arctocyonids are listed as the first creodont carnivores and also as condylarths. The earliest members of the Deltatheridia are also listed as insectivores and the latest as creodont carnivores. Rather than impose an arbitrary system of classification that would at the same time necessitate major changes in stratigraphical range, the various taxa are listed as submitted by contributors. Thus certain groups have a multiple documentation. This situation seems genuinely to reflect the real difficulty of assigning the small generalised mammals from the late Mesozoic and basal Tertiary to clearly defined orders. The uncertainty in this aspect of the documentation is therefore retained without apology. [L.B.H.T.] Subclass eotheria Order docodonta Family Morganucodontidae Kühne First and Last, Trias Rhaet or Jur Hett: Morganucodon Kühne, Glamorgan, Wales. Constituent genera: Morganucodon Kühne, Sinoconodon (in part) Patterson and Olson, Erythrotherium Crompton, Eozostrodon Parrington, Tricuspes F. von Huene. Comment: Morganucodon also comes from the Lu Feng Beds of Yunnan China, Erythrotherium from the Basutoland ‘Red Beds’ and Eozostrodon from Somerset, England. None of these localities can be dated more closely than U. Trias-L. Jur. They have not been included in the time-chart. Family docodontidae Simpson First and Last,