Many endemic Mascarene birds, including the dodo, are descended from South Asian ancestors, and the British palaeontologist Julian Hume has proposed that this may also be the case for all parrots there. Sea levels were lower during the Pleistocene, so it was possible for species to colonise some of these less isolated islands. Although most extinct parrot species of the Mascarenes are poorly known, subfossil remains show that they shared common features such as enlarged heads and jaws, reduced pectoral bones, and robust leg bones. Hume has suggested that they all have a common origin in the radiation of the tribe Psittaculini, members of which are known as Psittaculines, basing this theory on morphological features and the fact that "Psittacula" parrots have managed to colonise many isolated islands in the Indian Ocean. The Psittaculini could have invaded the area several times, as many of the species were so specialised that they may have evolved significantly on hotspot islands before the Mascarenes emerged from the sea. Other members of the genus "Psittacula" from the Mascarenes include the extant echo parakeet ("Psittacula eques echo") of Mauritius, as well as the extinct Réunion parakeet ("Psittacula eques eques"), and Mascarene grey parakeet ("Psittacula bensoni") of both Mauritius and Réunion.