 The Rodrigues solitaire shared traits with the dodo , its closest relative , such as size and features in the skull , pelvis and sternum . It differed in other aspects ; it was taller and more slender than the dodo and had a smaller skull and beak , a flatter skull roof and larger orbits . Its neck and legs were proportionally longer , and the dodo did not possess an equivalent to the carpal knob of the Rodrigues solitaire . Many skeletal features of the Rodrigues solitaire and dodo that are unique among pigeons have evolved to adapt to flightlessness . Their pelvic elements were thicker than those of flighted birds ( to support their greater weight ) , and their pectoral region and wings were paedomorphic ( underdeveloped , retaining juvenile features ) . However , the skull , trunk and pelvic limbs were peramorphic , which means they changed considerably with maturity . 
