 It was estimated that the relatives of the two species moved to the island about 35 million years ago, when a land bridge between Nazareth (Rodrigues) or St. Brandon banks and Mauritius formed.Many of the skeletal features that distinguish the dodo and the Rodrigues solitaire, its closest relative, from pigeons have been attributed to their flightlessness.The pelvic elements were thicker than those of flighted pigeons to support the higher weight, and the pectoral region and the small wings were paedomorphic, meaning that they were underdeveloped and retained juvenile features.