 UA 8699 was discovered in a joint study by Stony Brook University and the University of Antananarivo ( UA ) and placed in the collections of the latter as specimen 8699 . It was found at a locality named MAD93 @-@ 95 in the Anembalemba Member of the Maevarano Formation , which is Maastrichtian ( latest Cretaceous ) in age . The locality is in the Mahajanga Basin of northwestern Madagascar . Several other mammals have been recovered from similarly aged Madagascar deposits , but most are also known from very limited material . These include the gondwanathere Lavanify , an indeterminate multituberculate , and a few other indeterminate teeth , as well as a nearly complete skeleton representing an otherwise unknown mammalian lineage . In a 2001 Nature paper , David Krause announced the discovery of UA 8699 and argued for marsupial affinities of the specimen . Because the specimen is so fragmentary , he refrained from assigning a new scientific name to the tooth . Two years later , Alexander Averianov , David Archibald , and Thomas Martin favored a placental interpretation in a paper in Acta Palaeontologica Polonica , noting that the specimen was essentially similar to the zhelestid Lainodon . In a 2006 review of some of the Cretaceous vertebrates of Madagascar , Krause and colleagues continued to consider the specimen as a marsupial and announced that an upcoming paper by Case would make the case for marsupial affinities more fully . 
