VERTEBRATE PALEONTOLOGY IN 1910 



By R LYDEKKER 



So far at least as the highest class of animals concerned is con- 

 cerned, the most important palaeontological work published 

 during the year under review is undoubtedly Professor H. T. 

 Osborn's The Age of Mammals} To give an adequate summary 

 of the contents of this valuable work is quite impossible in this 

 article ; but it may be mentioned that the whole subject is treated 

 in an original and to a great extent novel manner, special atten- 

 tion being directed to the palaeogeography of the countries of 

 the world, and to former connections between areas now widely 

 sundered. Whilst urging the existence of a former land connec- 

 tion between Australia and South America, by way of the 

 Antarctic, the author refuses to admit any such connection 

 between South America and Africa, believing that the former 

 country received its early vertebrate fauna from the north. 



In regard to the puzzling problem of the origin of the 

 marsupials of Australia, Professor Osborn argues that this fauna 

 must have come either from south-western Asia or from South 

 America. The first immigrants into the country were, it is 

 urged, almost certainly arboreal opossum-like animals, from 

 which the rest of the marsupial fauna developed within the 

 country itself. On this hypothesis the fossil thylacines of 

 Patagonia (assuming that American palaeontologists are justified 

 in regarding the Patagonian carnivores as such) must either 

 have come from Australia or have been independently developed 

 in South America. If independently developed, which seems 

 unlikely, they afford, of course, no evidence as to an Australian- 

 American connection. On the other hand, if they came from 

 Australia they indicate, in the first place, the Asiatic origin of 

 the marsupials of that island-continent, and also that the ancestral 

 Australian marsupials reached their present habitat long before 

 the Miocene ; this being practically the view expressed by myself 

 in 1896.2 



' New York, the Macmillan Company, 1910. 

 * A Geographical History of Mammals, p. 56. Cambridge. 

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