''Murrayglossus'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

echidna Echidnas (), sometimes known as spiny anteaters, are quill-covered monotremes (egg-laying mammals) belonging to the Family (biology), family Tachyglossidae , living in Australia and New Guinea. The four Extant taxon, extant species of echidnas ...

from the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. It contains a single species, ''Murrayglossus hacketti'', also called Hackett's giant echidna. Though only from a few bones, researchers suggest that ''Murrayglossus'' was the largest monotreme to have ever lived, measuring around long and weighing around . 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 and weighing 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 In human anatomy, the lesser trochanter is a conical, posteromedial, bony projection from the shaft of the femur. It serves as the principal insertion site of the iliopsoas muscle. Structure The lesser trochanter is a conical posteromedial p ...

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

condyle A condyle (;Entry "condyle"
in

Discoveries

Fossils of ''Murrayglossus hacketti'' were discovered in

Mammoth Cave Mammoth Cave National Park is a List of national parks of the United States, national park of the United States in south-central Kentucky. It encompasses portions of Mammoth Cave, the List of longest caves, longest known cave system in the worl ...

, 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 In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''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 Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

and leg bones, and the cranial material is completely absent, making ''M. hackettis 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 Arnhem Land is a historical region of the Northern Territory of Australia. It is located in the north-eastern corner of the territory and is around from the territorial capital, Darwin, Northern Territory, Darwin. In 1623, Dutch East India Compa ...

in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

may represent ''M. hacketti'' or the extant

western long-beaked echidna The western long-beaked echidna (''Zaglossus bruijnii'') is one of the four Extant taxon, extant echidnas and one of three species of ''Zaglossus'' that occurs in New Guinea. Originally described as ''Tachyglossus bruijnii'', this is the type spe ...

(''Zaglossus bruijni'').

References

* {{Taxonbar, from=Q2300807 Pleistocene mammals of Australia Prehistoric monotremes Fossil taxa described in 2022 Taxa named by Tim Flannery