Box jellyfish
In Australia (mainly northern; however, box jellyfish can live in subtropical waters as far south as Sydney, with "Carybdea marsupialis" being recorded as far south as Bermagui, Sapphire Coast) the highest risk period for the box jellyfish is between October and May, but stings and specimens have been reported all months of the year. Similarly, the highest risk conditions are those with calm water and a light, onshore breeze; however, stings and specimens have been reported in all conditions.
Kimberella
All the "Kimberella" fossils found so far are assigned to one species, "K. quadrata". The first specimens were discovered in Australia in 1959. They were originally classified as jellyfish by Martin Glaessner and Mary Wade in 1966, and then as box jellyfish by Wade in 1972, a view that remained popular until the fossils of the White sea region were discovered; these prompted a reinterpretation. Research on these specimens by Mikhail A. Fedonkin, initially with Benjamin M. Waggoner in 1997, led to "Kimberella" being recognised as the oldest well-documented triploblastic bilaterian organism — not a jellyfish at all.