The animals of Australia : mammals, reptiles and amphibians / by A.H.S. Lucas ; assisted by W.H. Dudley Le Souëf.
- Arthur Henry Shakespeare Lucas
- Date:
- 1909
Licence: In copyright
Credit: The animals of Australia : mammals, reptiles and amphibians / by A.H.S. Lucas ; assisted by W.H. Dudley Le Souëf. Source: Wellcome Collection.
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![Cretaceous seas separated the East from the West, and in consequence these have -worked out their destinies to a considerable extent apart. South-West Australia has suffered more complete isolation tlian the other Australian Regions, for the barriers of the seas were succeeded by the liarriers of the great Deserts. The existing animals of Australia are the descendants, often moditied almost out of recognition, of the animals of these ]>ast times. A Mesozoic stock has been isolated in the main for long geologic periods of time. The originals of our present Amphibia and of onr Lizards, and primitive iMammalia conqirise all that we can recognize of onr Triassic pioneers. Strangely enough, however, it would appear that the genera Mynnecohiiis and (Jcratodus have persisted unaltered to the present. The most ancient and most primitive section of the iMannnals of all the -world, the egg-laying IMonotremes, has survived, and most likely originated in Australasia. The Platypus is confined to an Eastern stri]) from South Queensland to Tasmania. The Spiny Ant-eaters (TTedgehogs or Porcupines of the vernacular) have a -wide range. They are found in Tasmania and all over Australia, while a rather diff'erent form occurs in New Guinea. Both have become highly specialised for very definite and peculiar modes of life, and hence they are in external appearance as unlike as possible, and must be strikingly diff'erent from the group of Reptiles from which they sprung. The Mamipials, which form the bulk of the native Mammals of Australia, have had an exceedingly interesting history. Fossil remains of small forms, which may be looked upon as primitive mammals from which both the present ^Marsupials and the other existing mammals of the world have originated, have been found in the Triassic rocks of Europe and North America, -while others more distinctly mammalian occur in Jurassic beds. However evolved from these small and simple Mesozoic forms and others the remains of which have not been discovered, the iMarsupial section was unable to hold its own in the Old World, and has survived only in America as far north as the Southern United States, where the carnivorous Opossums are met Moth, and in Tasmania, Australia and Papua. A fortunate isolation enabled them to develop on their own lines in Australia. With less highlv convoluted brains, thev have-](https://iiif.wellcomecollection.org/image/b28108759_0018.jp2/full/800%2C/0/default.jpg)
