Kollikodon is an australosphenidan species, often classified as a monotreme but more recently recovered as an outgroup. It is known only from an opalised dentary fragment, with one premolar and two molars in situ, as well as a referred maxillary fragment containing the last premolar and all four molars. The fossils were found in the Griman Creek Formation at Lightning Ridge, New South Wales, Australia, as was Steropodon.

Temporal range: Cenomanian, 99–96 Ma
Opalised jaw of Kollikodon (backlit)
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Yinotheria
Infraclass: Australosphenida
Family: Kollikodontidae
Flannery, Archer, Rich & Jones, 1995
Genus: Kollikodon
Flannery, Archer, Rich & Jones, 1995
K. ritchiei
Binomial name
Kollikodon ritchiei
Flannery, Archer, Rich & Jones, 1995
  • Hotcrossbunodon (informal)

Kollikodon lived in the Late Cretaceous period, during the Cenomanian age (99-96 million years ago).

Like Steropodon, Kollikodon was a relatively large mammal for the Mesozoic. The molars have a length of around 5.5 mm and a width of between about 4 and 6 mm (Clemens et al., 2003). Based upon these data, the potential body length could be up to a metre.[1] Assuming the accuracy of such a guess, Kollikodon would be a contender for the largest Mesozoic mammal known, along with other possible giants such as Repenomamus, Schowalteria, and Bubodens.

Aside from its size, it is difficult to say what Kollikodon looked like. It is certain that its teeth were specialised to crush food, being perhaps a shellfish-eater or herbivore. The description of the upper jaw showed that it was strongly specialised, with molars being subdivided into numerous rounded cuspules, some of which exhibit pits, possibly the result of crushing hard items.[2]

Both Kollikodon and Steropodon can be found at the Australian Museum in Sydney, along with Eric, the opalised pliosaur.


Kollix is an ancient Greek word (κολλίξ) for a bread roll. The strange teeth of Kollikodon, when seen from above, resemble hot cross buns, traditionally toasted and eaten on Good Friday. Originally, Michael Archer wanted to name it "Hotcrossbunodon", but met disapproval from his associates.[3]


  1. ^ Anne Weil, Mammalian palaeobiology: Living large in the Cretaceous, Nature 433, 116-117 (13 January 2005) doi:10.1038/433116b; Published online 12 January 2005
  2. ^ Pian, Rebecca; Archer, Michael; Hand, Suzanne J.; Beck, Robin M.D.; Cody, Andrew (2016). "The upper dentition and relationships of the enigmatic Australian Cretaceous mammal Kollikodon ritchiei" (PDF). Memoirs of Museum Victoria. 74: 97–105. doi:10.24199/j.mmv.2016.74.10. ISSN 1447-2546.
  3. ^ John A. Long; Michael Archer; Timothy Flannery; Suzanne Hand (2002). Prehistoric mammals of Australia and New Guinea: One hundred million years of evolution. Baltimore, Maryland: Johns Hopkins University Press. p. 39. ISBN 978-0801872235.
  • Flannery, T.F., Archer, M., Rich, T.H., Jones, R. (1995) "A new family of monotremes from the Cretaceous of Australia". Nature 377: 418-420.

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