the echo parakeet was mainly known from fossil bones, as it was the Mauritian parrot most commonly found in cave deposits, and that skeletons are rare in museum collections. Hume pointed out that many birds endemic to the Mascarene Islands are derived from South Asian ancestors, and that a South Asian provenance was probable for the parrots, as well. Sea levels were lower during the Pleistocene, so species island hopping to the isolated islands was possible. In spite of most mascarene parrots being poorly known, fossil remains show that they shared features such as enlarged heads and jaws, reduced pectoral elements, and robust leg elements. Hume suggested they shared a common origin within the Psittaculini radiation, based on morphological features and the fact that Psittacula parrots have managed to colonise many isolated islands in the Indian Ocean. In 2008, Cheke and Hume suggested that this group may have invaded the area several times, as many of the species were so specialised that they may have diverged on hot spot islands before the Mascarenes emerged from the sea. A 2011 DNA study by British biologist Samit Kundu and colleagues found the echo parakeet samples grouped between two subspecies of the rose-ringed parakeet, P. k. krameri and P. k. borealis. They suggested that since some of the Indian Ocean island species had diverged early within their clades, including the echo parakeet within P. krameri, Africa and Asia may have been colonised from there rather than the other way around. They found the echo parakeet to have diverged between 3.7 and 6.8 million years ago, which, if correct, could imply that speciation had occurred before the formation of Mauritius. These researchers were unable to extract DNA from the Edinburgh specimen. In 2015, British geneticist Hazel Jackson and colleagues managed to obtain DNA from a toe pad of the Edinburgh specimen and compare it with specimens from Mauritius. They found that within the P. krameri clade, Newton's parakeet from Rodrigues was ancestral to the Mauritius and Réunion parakeets, diverging from them 3.82 million years ago and that the latter two had diverged just 0.61 million years ago, differing by 0.2% from each other. The researchers concluded that the low level of divergence between the Mauritius and Réunion populations was consistent with them being distinct at the subspecific level. The following cladogram shows the phylogenetic position of the Mauritius and Réunion subspecies, according to Jackson