 The oldest known fossils of an ancestral water rail are bones from Carpathia dated to the Pliocene ( 5 @.@ 3 – 1 @.@ 8 million years ago ) . By the late Pleistocene , two million years ago , the fossil evidence suggests that the water rail was present across most of its present range . This species is surprisingly well recorded , with over 30 records from Bulgaria alone , and many others from across southern <unk> and China . A rail from <unk> , Rallus <unk> , was smaller but more robust than the water rail , and probably had poorer flight abilities . In the Quaternary , the island lacked terrestrial mammals , and this distinctive form was presumably descended from its continental relative . It became extinct at about the same time as humans arrived on the island , between 16 @,@ 700 and 5 @,@ 300 BC . The nominate race of water rail is now a very rare resident on <unk> . 
