who described it?
John Gould
Rock parrot
Described by John Gould in 1841, it is a small parrot long and weighing with predominantly olive-brown upperparts and more yellowish underparts. 
where is rock parrot found? It is a species of grass parrot native to Australia.
wiki:8594310
Rock parrot [SEP] Introduction
The rock parrot ("Neophema petrophila") is a species of grass parrot native to Australia. Described by John Gould in 1841, it is a small parrot long and weighing with predominantly olive-brown upperparts and more yellowish underparts. Its head is olive with light blue forecheeks and lores, and a dark blue frontal band line across the crown with lighter blue above and below. The sexes are similar in appearance, although the female tends to have a duller frontal band and less blue on the face. Two subspecies are recognised. Rocky islands and coastal dune areas are the preferred habitats for this species, which is found from Lake Alexandrina in southeastern South Australia westwards across coastal South and Western Australia to Shark Bay.