Belgian-British zoologist George Albert Boulenger described P. cupreus in 1896 from a specimen collected from the Murray River, distinguishing P. darwiniensis from P. australis by the shape of the frontal scale. Austrian zoologist Franz Werner described Pseudechis denisonioides from Eradu, Western Australia in 1909.
In 1896, Belgian-British zoologist George Albert Boulenger described *P. cupreus* based on a specimen collected from the Murray River. He distinguished *P. darwiniensis* from *P. australis* by the shape of the frontal scale. Austrian zoologist Franz Werner described *Pseudechis denisonioides* in 1909 from Eradu, Western Australia.