Sydney: Over 500 million-year-old fossil eyes of the extinct Anomalocaris have been found in a pristine condition.

They show the world's first apex predator had extremely acute vision, rivalling or exceeding that of most living insects and crustaceans.

The team behind this discovery includes University of Adelaide researcher Michael Lee and Jim Jago, of the South Australian Museum, and led by John Paterson of University of New England, US.

The metre-long Anomalocaris is the stuff of nightmares and sci-fi movies which sat at the apex of the earliest food chains because of its large body size, formidable grasping claws at the front of its head and a circular mouth with razor-sharp serrations, the journal Nature reports.

The discovery of its stalked eyes - showing astonishing details of its optical design - from a 515 million-year-old deposit on Kangaroo Island in South Australia now confirms it had super vision to support its predatory lifestyle, according to a University of Adelaide statement.

The fossils represent compound eyes - the multi-faceted variety seen in arthropods such as flies, crabs and kin - and are among the largest to have ever existed, with each eye up to three cm in length and containing over 16,000 lenses.

The discovery of powerful compound eyes in Anomalocaris confirms it is a close relative of arthropods, and has other far-reaching evolutionary implications.

Arthropods include invertebrates such as insects, spiders, crustaceans, scorpions and centipedes.