Raphus solitarius probably never existed. A large flightless ibis (extinct) from Reunion now bears the name Threskiornis solitarius. It is generally thought that this ibis is probably what the reported 'dodo' on the island actually were (and paintings of the 'dodo' were works of imagination based on the Mauritius dodo)
There's a body of opinion that the original paintings of Mauritius Dodos were exaggerated too. I was watching a video at the NHS recently about this- by comparing the structures of modern day Pigeons and other species related/comparable with Dodo, scientists there think that their bulbous appearance, particularly of the crop and head/neck regions, were exaggerrated by early painters, and modern scientific artists' recreations have now come up with a slightly more streamlined, if still improbable-looking bird.
