They form the most variably sized bird order in terms of length. The smallest of the parrots is the pigmy parrot ("Micropsitta pusio") with an adult weight of and a length of . With a length (from the top of its head to the tip of its long pointed tail) of about , the hyacinth macaw ("Anodorhynchus hyacinthinus") is longer than any other species of parrot, although half that length is tail.