The genus and
species were named by the
Argentinian paleontologist José Bonaparte in 1986.
Gondwanatherium means
Gondwana beast. The position of gondwanatherians within class Mammalia is not yet clear. The
type species Gondwanatherium patagonicum was discovered in
Los Alamitos Formation,
Río Negro Province,
Patagonia,
Argentina in deposits dating to the Upper Cretaceous period. Though earlier than
Sudamerica,
Gondwanatherium is considered more anatomically derived (advanced). Thus, an ancestral lineage outlived their later, more specialized descendants. It is estimated to have weighed ~2.4 kg. ==References==