When C. Jouanin and P. Paulian surveyed beds of subfossil bones on Île Amsterdam in the subantarctic Indian Ocean in 1960, they found almost only bones of seabirds, but also some bones of what later was described as the Amsterdam Island Duck (Anas marecula Olson & Jouventin) – and – the mummified body of a middle-sized rail.
The two just wrote some kind of short note , that later, in 1977, was translated by Storrs L. Olson.:
„A mummy of a small rail was discovered in a tunnel in a lava flow, under a block that had no doubt protected it from moisture. A sketch was made in situ, as well as taking measurements of the beak (22 mm), the tarsus (40) and the middle toe without claw (34), but the mummy fell to dust when an attempt was made to pick it up. In this case one cannot infer the former existence of a rail peculiar to New Amsterdam, although it would be perfectly likely (endemic species of this order exist on most isolated islands), for the measurements cited coincide with those of a skin of a Corncrake (Crex crex Linnaeus) in the British Museum collected 100 miles to the south of Madagascar. Still, this identification is not wholly satisfactory: the mummy did not have the bulk nor the heavy bill of a Corncrake, and it is most regrettable not to have been able to remove it.“ 
The Amsterdam Island Rail very, very, very likely, if not absolutely definitely, was an endemic species, that indeed may have descended from the trampy Corncrake, a species that inhabits parts of western Asia and Europe, but on its migrations, pops up almost everywhere on Earth!
Imagine how many such endmic rails may have existed before mankind spread all over the planet, it must have been thousands …!
 C. Jouanin; P. Paulian: Recherche das ossements d’oiseaux provenant de l’île Nouvelle-Amsterdam (Océan Indien). Proceedings of the XIIth International Ornithological Congress, Helsinki: 368-372. 1960
 Storrs L. Olson: A synopsis of the fossil Rallidae. In: Sidney Dillon Ripley: Rails of the World – A Monograph of the family Rallidae. Codline. Boston 1977