The upland moa lived on the South Island of New Zealand, and was predominantly found in alpine and sub-alpine environment where it fed on flowers, herbs and other vegetation.

The upland moa was named as Dinornis didinus in 1883 by Richard Owen from mummified material found in 1878 by H. L. Squires in Queenstown, New Zealand and subsequently sent to the British Museum.

[4] In 2005, a genetic study suggested that Megalapteryx benhami, which had previously been considered a junior synonym of M. didinus, may be a valid species after all.

[8] Unlike other moas, it had feathers covering all of its body but the beak and the soles of its feet, an adaptation to living in cold environments.

[10] Studies of the upland moa's coprolites have provided evidence that branchlets of trees such as Nothofagus, various lake-edge herbs, tussock, and nectar-rich flowers made up part of its diet.

[20][21] Based on the pollen present in the coprolites, it is suggested they had a similar lifestyle to the living takahē, feeding in high alpine areas during the summer and descending to lower altitude forests in the winter.