The description of a new species and genus was published in 2019, emerging from research undertaken by
Trevor Worthy,
Suzanne Hand,
Mike Archer, R. Paul Scofield and Vanesa L. De Pietri. Alan Tennyson's and Te Papa's key role in this discovery was later acknowledged in a correction published in 2021.
Heracles inexpectatus was described from two incomplete
tibiotarsi (leg bones), a left one and a right one, probably from the same individual, that were discovered in 2008. The left bone was nominated as the holotype. The fossils were originally presumed to be from an eagle, but were re-inspected after a PhD student at
Flinders University noted that the bone morphology was significantly different from typical eagles. The etymology of the generic epithet
Heracles alludes to the earlier naming of a genus,
Nelepsittacus, also found in the St Bathan Fauna, which referred to a mythical king
Neleus who was slain by the Greek hero
Herakles, who also slew all of his sons, save for Nestor. The authors distinguished the new species with the epithet
inexpectatus to describe their astonishment at the unexpected discovery of an enormous parrot-like bird from the Miocene epoch. The etymology of the nickname "Squawkzilla" is a portmanteau of the words "squawk", an onomatopoeic word for
the sound of a parrot, and "
-zilla", a suffix denoting large size, derived from the fictional giant creature
Godzilla. == Description ==