Kookaburra larger group known as "kingfishers", kookaburras are not closely associated with water. The genus "Dacelo" was introduced by the English zoologist William Elford Leach in 1815. The type species is the laughing kookaburra. The name "Dacelo" is an anagram of "Alcedo", the Latin word for a kingfisher. A molecular study published in 2017 found that the genus "Dacelo", as currently defined, is paraphyletic. The shovel-billed kookaburra in the monotypic genus "Clytoceyx" sits within "Dacelo". Four species of kookaburra can be found in Australia, New Guinea, and the Aru Islands. Kookaburras are sexually dimorphic. This is noticeable in the blue-winged and
Rufous-bellied kookaburra and rufous in females and immature birds. Rufous-bellied kookaburras are smaller than other kookaburra species at around as against the laughing kookaburra's and about as against the laughing kookaburra’s . Despite this major size difference, the rufous-bellied kookaburra has been known to form (infertile) hybrids with all other kookaburra species, though available genetic studies suggest it is clearly the most distant of the four. This kookaburra is unusual in that it occupies dense rainforests (as opposed to the open country preferred by other kookaburras) and does not live in cooperative breeding family groups but singly or when breeding in pairs.