PLEISTOCENE ECOLOGY AND BIOGEOGRAPHY 409 



WEST INDIAN VERTEBRATES AND GALAPAGOS TORTOISES 



Late Pleistocene and sub-Recent insular extinction throughout 

 most of the world appears to have been intense. Certain oceanic 

 islands exhibit the phenomenon of extermination without replace- 

 ment noted in North and South America. Giant marsupials inhabited 

 Australia (Gill, 1955), large flightless birds survived in New Zealand 

 at least until 1300 a.d. (Deevey, 1955), and giant lemurs, tortoises, 

 and large birds lived in Madagascar (Sibree, 1915). West Indian 

 mammals, reptiles, and birds experienced extermination both of 

 relatively medium-sized genera (tortoises and ground sloths) and of 

 many smaller rodents. In this respect West Indian extinction differs 

 from the continental record. Summary articles by Allen (1911) and 

 Matthew (1919) have been superseded by Simpson's valuable zoo- 

 geographic synthesis (1956). Allen (1942) discussed most of the ex- 

 tinct mammals. Except for Cuban ground sloths (Allen, 1918; 

 Aguayo, 1950) and Jamaican bats and rodents (Anthony, 1920; 

 Koopman and Williams 1951; Williams, 1952b), the distribution of 

 most of the extinct mammals is covered in Miller and Kellogg's 

 Checklist (1955). 



The extinction chronology is rather baffling and is not simplified 

 by the possibility that certain forms such as Nesophontes may yet be 

 found to survive in remote mountainous districts. I am indebted to 

 K. F. Koopman for pointing out that more than 300 years elapsed 

 between discovery of the islands by western man and the first serious 

 scientific description of their fauna. Extermination in this interval, 

 perhaps at the hands of superior competitors as Rattus, or as the 

 result of clearing and cultivation, will be difficult to distinguish from 

 prehistoric extermination. Nesophontes, for example, appears to 

 have been contemporaneous with Rattus. In contrast Testudo and 

 various ground sloths almost surely were not present at the time of 

 the conquest. Ground sloths may have existed into the ceramic 

 period (Aguayo, 1950), and the giant rodent Quemisia was ap- 

 parently known to Oviedo (Allen, 1942), but there is no certain 

 evidence of other large hystricomorphs (Elasmodontomys, Clidomys, 

 and Amblyrhiza) in post-Columbian middens and it is most unlikely 

 that their presence would have gone unrecorded by early observers. 



Simpson listed twenty-two extinct genera of terrestrial mammals 

 in the Greater Antilles. Even assuming some unnecessary splitting, 

 the fossil fauna is quite impressive. By comparison, the present sur- 



