In 2018, the American ornithologist Kaiya L. Provost and colleagues found the Mascarene parrot (Mascarinus mascarinus) and Tanygnathus species to group within Psittacula, making that genus paraphyletic (an unnatural grouping), and stated this argued for breaking up the latter genus. To solve the issue, the German ornithologist Michael P. Braun and colleagues proposed in 2019 that Psittacula should be split into multiple genera. They placed the echo parakeet in the new genus Alexandrinus, along with its closest relatives. In 2020, Jansen and Cheke pointed out that Marinet's plate that serves as the type illustration of P. eques differs considerably in colouration between copies (some have yellow on the upper breast while others do not, for example). They concluded that these were hand-coloured by different people after an unidentified master plate by Martinet, but since it cannot be established which of the copies that accurately represents the specimen they depicted, Jansen and Cheke found it safer to rely on the description by Brisson. In 2021, Jansen and Cheke found that the variation in plumage seen in males in Mauritius is wide enough to encompass that known from the descriptions, illustrations and skin from Réunion. They therefore concluded that the two populations belonged to a single species with no subspecies. They also found that there was no evidence to reliably confirm what island the Edinburgh skin was collected from, and that since it was unknown to the French encyclopaedists that echo parakeets also lived on Mauritius, birds matching their descriptions were assigned to Réunion by default. Description The echo parakeet is long and weighs , which makes it smaller than the other, now extinct, Mauritian parrots. The wingspan is , each wing is long, the tail is , the culmen is , and the tarsus is . The female is somewhat smaller than the male on average. It is generally green, with a darker back and yellowish underside. The male is lighter and the female darker overall. It has two ring collars on the neck, which are incomplete, failing to meet at the back. The male has one black and one pink collar, which appears crescent shaped in side view, and has blue suffusion above it. The female has an indistinct black collar and a green collar, which becomes dark green across the cheeks and yellow-green at the back of the neck. The male has a black, narrow line running from the