 UA 8699 ( University of Antananarivo specimen 8699 ) is a fossil mammalian tooth from the Cretaceous of Madagascar . A broken lower molar about 3 @.@ 5 mm ( 0 @.@ 14 in ) long , it is from the Maastrichtian of the Maevarano Formation in northwestern Madagascar . Details of its crown morphology indicate that it is a boreosphenidan , a member of the group that includes living marsupials and placentals . David W. Krause , who first described the tooth in 2001 , interpreted it as a marsupial on the basis of five shared characters , but in 2003 Averianov and others noted that all those are shared by zhelestid placentals and favored a close relationship between UA 8699 and the Spanish zhelestid Lainodon . Krause used the tooth as evidence that marsupials were present on the southern continents ( Gondwana ) as early as the late Cretaceous and Averianov and colleagues proposed that the tooth represented another example of faunal exchange between Africa and Europe at the time . 
