Image: From above
Methana (Bark) Cockroach - note prominent creamy/ white horseshoe marking on the shield.
Most cockroaches in the BLATTIDAE family are flightless except for Methana species. Methana marginalis is a native species found throughout Queensland. (Source: www.ento.csiro.au)
Image: From side
The Methana genus has been around for 115-118 million years. (reported on Scribblygum)
It is popularly suggested that cockroaches will "inherit the earth" if humanity destroys itself in a nuclear war. Cockroaches do indeed have a much higher radiation resistance than vertebrates, with the lethal dose perhaps 6 to 15 times that for humans. However, they are not exceptionally radiation-resistant compared to other insects, such as the fruit fly .