Madeiran Thrush (Turdus sp.)
This up to now undescribed taxon is known only on the basis of subfossil remains that were found (quite commonly) on the island of Madeira. 
The Madeiran Thrush was a large, long-legged species, apparently adapted to a terrestrial lifestyle, it is not known if the species was flightless, but it was very likely a poor flyer and a typical tame (naive) island bird with no fear for humans or other mammals ….
Today, the only species of thrush inhabiting the island of Madeira is the native Blackbird (Turdus merula ssp. cabrerae Hartert) with a subspecies that also inhabits the Canary Islands.
There is a quite interesting account from 1823, made by T. Edward Bowdich, who apparently was the only person who has ever recorded this species, he even shot one on the island of Porto Santo.:
“We shot the falco oesalon; the upupa capensis, which I presume was not known inhabit so far north; the larus canus, said by the natives to be blown over from the African coast; the columba livia, of which there are large flocks; a turdus; the loxia enucleator, and a larger corythus.” 
About the thrush he makes to following additional comment.:
“The back and belly are brown, with patches of yellow, the wings and tail brown; the beak is strong, and of a brown colour, except the first half of the lower mandible, which is yellow.” 
 T. Edward Bowdich; Sarah Lee Bowdich: Excursions in Madeira and Porto Santo, during the autumn of 1823, while on his third voyage to Africa. London: G. B. Whittaker 1825
 Harald Pieper: The fossil land birds of Madeira and Porto Santo. Bocagiana 88: 1-6. 1985