The article presents a preliminary morphological description of the holotype of Megaloceros giganteus (Blumenbach, 1799) that serves for the description of the species. The article proposes a taxonomical and morphological revision of the nominotypical subspecies M. giganteus giganteus and morphological comparison with other subspecies of M. giganteus. The cluster analysis of diagnostic craniodental and antler characters revealed the systematic position and phylogenetic relationships of M. giganteus with other cervid groups. The genus Praedama is regarded as a closely related phylogenetic branch that linked to the direct cursorial forerunner of Megaloceros that evolved in the middle latitudes of Western Siberia and northern Kazakhstan. The genus Dama has a distant relationship with Megaloceros and represents an earlier phylogenetic branch that evolved in the Ponto-Mediterranean area. The article discusses the secondary adaptations of M. giganteus forms to forest and woodland habitats in Europe and general paleobiogeographic features of the Megaloceros lineage.