[3] The Koonwarra fossil bed was found by accident in 1961 during roadworks to realign a segment of the South Gippsland Highway.

Dating from the early Cretaceous 115 million years ago, it is composed of mudstone sediment thought to have been laid down in a freshwater (possibly cool-climate subalpine) lake.

The site is an important element of Australia's fossil record, with plants, insects (including mayflies, dragonflies, cockroaches, beetles, fleas, flies and wasps), spiders, crustaceans and fish recovered.

[4] Among them is the unusual finding of a fossil horseshoe crab described as Victalimulus mcqueeni.

[5] Small segments of a leafy twig have been recovered that were thought to be one of the oldest angiosperms (flowering plants) discovered; more recent examination reports anatomy more typical of a gnetophyte, a group of plants for which there is a scant fossil record.