''Malleodectes'' 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 of unusual marsupial, first discovered in 2011 at Riversleigh,

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

Taxonomy

The description of the new genus and two species, was published in 2011, based on fossilised type material discovered at a Riversleigh site. The type species is named ''Malleodectes mirabilis'' and the second description published as ''Malleodectes moenia''; their generic epithet combines terms derived from the Latin, ''malleo'' meaning hammer, and Ancient Greek, ''dectes'' for biter, in reference to the unusual dentition. ''Malleodectes'' was classified as the sole genus of Malleodectidae in a 2016 revision, with the family allied to

Dasyuromorphia Dasyuromorphia (, meaning "hairy tail" in Greek) is an order comprising most of the Australian carnivorous marsupials, including quolls, dunnarts, the numbat, the Tasmanian devil, and the extinct thylacine. In Australia, the exceptions include ...

. A 2025 study assigned the genus '' Barinya'' and, tentatively, the new genus '' Weirdodectes'' to the family Malleodectidae.

Description

Malleodectes-mirabilis-using-its-massive-ball-peen-like-P3-to-break-into-what-were

A marsupial with highly specialised dentition, an enlarged premolar with a flattened profile used to hammer open the shells of snails found in its wet forested environment. This tooth was compared by the authors to a genus of skinks, ''

Cyclodomorphus ''Cyclodomorphus'' is a genus of small to medium-sized skinks (family (biology), family Scincidae)."''Cyclodomorphus'' ". The Reptile Database. www.reptile-database.org. It belongs to the ''Egernia'' group which also includes the blue-tongued sk ...

'', and concluded this represented evolutionary convergence with the modern skinks that have similar adaptation to their diet of snails; the authors gave a generalised description of this unusual animal as a "marsupial-skink".

Scott Hocknull Scott Hocknull (born 1977) is a vertebrate palaeontologist and Senior Curator in Geology at the Queensland Museum in Brisbane. He was the 2002 recipient of the List of Young Australian of the Year Award recipients, Young Australian of the Year A ...

from the

Queensland Museum The Queensland Museum Kurilpa is the state museum of Queensland, funded by the government, and dedicated to natural history, cultural heritage, science and human achievement. The museum currently operates from its headquarters and general museu ...

noticed similarities to the modern pink-tongued skink (''Cyclodomorphus gerrardii''), a

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

specialised for eating

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

s. This suggests that ''Malleodectes'' was a specialised snail hunter. It could grow as large as a

ferret The ferret (''Mustela furo'') is a small, domesticated species belonging to the family Mustelidae. The ferret is most likely a domesticated form of the wild European polecat (''Mustela putorius''), as evidenced by the ferret's ability to inter ...

, and lived in the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, . A leading author on the research and description of the species, professor Michael Archer, said of the type species, "''Malleodectes mirabilis'' was a bizarre mammal, as strange in its own way as a koala or kangaroo …,". Fossil material associated with genus had been collected by workers at Riversleigh in the years leading to the crucial discovery of a juvenile jaw containing unerupted adult teeth. The juvenile specimen was found at a cave floor deposit with the remains of other animals, the AL90 site, and postulated to have fallen from its mother into a cave that once existed in the limestone formation.

References

{{Taxonbar, from=Q6744125 Miocene marsupials Prehistoric mammals of Australia Riversleigh fauna Fossil taxa described in 2011 Prehistoric marsupial genera Dasyuromorphs