 Gondwanatheres are a small group of mammals of uncertain phylogenetic affinities known from the late Cretaceous to the Eocene ( ~ 56 – 34 mya ) of the Gondwanan continents , known only from teeth and a few lower jaws . Upon their discovery in the 1980s , gondwanatheres were initially thought to be xenarthrans — part of the same group as living sloths , armadillos , and anteaters — but later workers have favored affinities with multituberculates ( a diverse group of fossil mammals ) or left the relationships of the gondwanatheres open . The group comprises two families . The family Ferugliotheriidae , whose members had low @-@ crowned teeth , occurs in the Campanian ( ~ 84 – 71 mya ) to Maastrichtian of Argentina . All other gondwanatheres , including Lavanify , are placed in the Sudamericidae , which have high @-@ crowned ( hypsodont ) teeth . These include Gondwanatherium from the Campanian and Maastrichtian of Argentina ; Sudamerica from the Paleocene ( ~ 66 – 56 mya ) of Argentina ; Lavanify ; at least one species from the Maastrichtian of India ; an unnamed species related to Sudamerica from the Eocene of Antarctica ; and an unnamed possible gondwanathere , TNM 02067 , from the Cretaceous of Tanzania . In 2007 , teams led by G.P. Wilson and G.V.R. Prasad independently described this animal as Dakshina and Bharattherium respectively ; as the latter name was published first , it is the correct name for this genus according to the Principle of Priority . Gondwanatheres have been interpreted as feeding on roots , bark , and abrasive vegetation or as the earliest grass @-@ eating mammals . 
