Zaglossus hacketti

Zaglossus hacketti is an extinct species of long-beaked echidna from Western Australia that is dated to the Pleistocene. It is known only from a few bones.[1] It was about 1 m long[1] and probably weighed about 30 kg (66 lb).[2] This makes it the largest monotreme known to have ever lived. Due to the lack of cranial material, placement of Z. hacketti into the modern long-beaked echidna genus Zaglossus is uncertain.[1][3]