Megalibgwilia is a genus of echidna known only from Australian fossils that incorporates the oldest-known echidna species. The genus ranged from the Miocene until the late Pleistocene, becoming extinct about 50,000 years ago. Megalibgwilia species were more widespread in warmer and moist climates. Their extinction can be attributed to increasing aridification in Southern Australia.[3]

Temporal range: MioceneLate Pleistocene
M. owenii humerus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Monotremata
Family: Tachyglossidae
Genus: Megalibgwilia
Griffiths, Wells and Barrie, 1991
Type species
Echidna owenii
Krefft, 1868
  • Megalibgwilia owenii (Krefft, 1868)
  • Megalibgwilia robusta (Dun, 1895)

Megalibgwilia was first described from a broken left humerus by Gerard Krefft in 1868 as "Echidna" owenii.[1] In the past, many researchers didn't recognize that "Echidna" ramsayi named by Richard Owen in 1884 represents a junior synonym,[4] though recent studies have reevaluated this.[2] Complete skulls and postcranial fossils have since been described. A second species, M. robusta, was described in 1895 by Australian paleontologist William Sutherland Dun. Megalibgwilia comes from Greek mégas (μέγᾰς) and Wemba Wemba libgwil (plus the Latin suffix -ia), meaning echidna.[5]

Although they are sometimes commonly referred to as giant echidnas, Megalibgwilia species are thought to have been similar in size to the contemporary western long-beaked echidna, but with slightly longer forearms.[6] They were smaller than a large species known from fossils in Australia, Murrayglossus. M. ramsayi fossils have been found in deposits across mainland Australia and on Tasmania. M. robusta has only been found in New South Wales.[6] Megalibgwilia was probably an insect-eater, like the short-beaked echidna, rather than a worm-eater like members of Zaglossus.[5]

M. robusta, once thought to be a species of Zaglossus, is the oldest-known echidna and the only known Miocene species.[5][2] It has been suggested that the supposed fossil platypus Ornithorhynchus maximus was based on a humerus of this species.[7][8]


  1. ^ a b Helgen, Kristofer M.; Miguez, Roberto Portela; Kohen, James; Helgen, Lauren (2012-12-28). "Twentieth century occurrence of the Long-Beaked Echidna Zaglossus bruijnii in the Kimberley region of Australia". ZooKeys (255): 103–132. doi:10.3897/zookeys.255.3774. ISSN 1313-2970.
  2. ^ a b c Flannery, Timothy F.; Rich, Thomas H.; Vickers-Rich, Patricia; Ziegler, Tim; Veatch, E. Grace; Helgen, Kristofer M. (2022). "A review of monotreme (Monotremata) evolution". Alcheringa: An Australasian Journal of Palaeontology. 46 (1): 3–20. Bibcode:2022Alch...46....3F. doi:10.1080/03115518.2022.2025900. S2CID 247542433.
  3. ^ Ashwell, Ken W.S.; Hardman, Craig D.; Musser, Anne M. (October 2014). "Brain and behaviour of living and extinct echidnas". Zoology. 117 (5): 349–361. doi:10.1016/j.zool.2014.05.002. PMID 25053446.
  4. ^ Owen, P. (1883). "Evidence of a Large Extinct Monotreme (Echidna Ramsayi, Ow.) from the Wellington Breccia Cave, New South Wales". Proceedings of the Royal Society of London. 36 (228–231): 273–275. doi:10.1098/rspl.1883.0073. JSTOR 109445.
  5. ^ a b c Griffiths, M.; Wells, R.T.; Barrie, D.J. (1991). "Observations on the skulls of fossil and extant echidnas (Monotremata:Tachyglossidae)". Australian Mammalogy. 14: 87–101.
  6. ^ a b Long, J., Archer, M., Flannery, T. and Hand, S. 2002. Prehistoric Mammals of Australia and New Guinea: One Hundred Million Years of Evolution. Johns Hopkins University Press. pp 45–47. ISBN 0-8018-7223-5.
  7. ^ Hall, B. K. (1999). "The paradoxical platypus". BioScience. 49 (3): 211–218. doi:10.2307/1313511. JSTOR 1313511.
  8. ^ Musser, A. M. (1999). "Diversity and relationships of living and extinct monotremes" (PDF). Australian Mammalogy. 21 (8–9).