Murrayglossus
Murrayglossus is a genus in the family Tachyglossidae. It contains a single species, Murrayglossus hacketti, the giant echidna, an extinct species of echidna from Western Australia that is dated to the Pleistocene. It is known only from a few bones. It was about long and probably weighed about 30 kg (66 lb). This makes it the largest monotreme known to have ever lived. Historically treated as a species of long-beaked echidnas, it was separated into its own genus "Murrayglossus" in 2022. The generic name combines the last name of paleontologist Peter Murray and "glossus", the Greek word for  tongue. Description. At around long, tall and about , "M. hacketti" was the largest monotreme known to have existed. "M. hacketti" had longer, straighter legs than any of the modern echidnas. Augee (2006) speculates that this feature made the animal more adept at traversing through thickly wooded forests. The main diagnostic characteristics of genus "Murrayglossus" are a set of femoral traits: a low femoral head; the very low position of the lesser trochanter relative to head (situated directly below the internal margin of the femur); the large trochanter that has a high position relative to the head; a flared medial epicondyle ; and obliquely oriented condyles. Discoveries. Fossils of "Murrayglossus hacketti" were discovered in Mammoth Cave, Western Australia, and excavated in 1909. They were found mixed with the remains of other taxa such as "Sthenurus" and "Macropus". Australian paleontologist Ludwig Glauert described the fossils in a 1914 publication. The specific epithet "hacketti" honours John Winthrop Hackett, "as a slight acknowledgement of his generous support which alone rendered the exploration of these caves possible.". The material is poor, mostly vertebra and leg bones, and the cranial material is completely absent, making "M. hacketti"'s historical classification into the genus "Zaglossus" uncertain. Some of  the fossils have incisions and burn marks, suggesting that "M. hacketti" was at least occasionally hunted by humans. Aboriginal rock art found in Arnhem Land in the Northern Territory may represent "M. hacketti" or the extant western long-beaked echidna ("Zaglossus bruijni").