''Apterodon'' ("without winged tooth") is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

hyaenodontid Hyaenodontidae (" hyena teeth") is a family of extinct predatory mammals from extinct superfamily Hyaenodontoidea within extinct order Hyaenodonta. Hyaenodontids arose during the early Eocene and persisted well into the early Miocene. Fossils of ...

mammals that lived from the late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

through the middle

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

epoch in

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. It is closely related to the African '' Quasiapterodon'', and together it, they comprise the hyainailurids subfamily

Apterodontinae Apterodontinae ("without winged tooth") is an extinct subfamily of hyainailourid hyaenodonts that lived in Africa and Europe during the late Eocene to middle Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends ...

. Uniquely among hyaenodonts, species of ''Apterodon'' were a

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

fossorial A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric eviden ...

mammals. They possessed strong forelimbs that were well equipped for digging, compared to those of modern

badgers Badgers are short-legged omnivores in the family Mustelidae (which also includes the otters, wolverines, martens, minks, polecats, weasels, and ferrets). Badgers are a polyphyletic rather than a natural taxonomic grouping, being united by the ...

, while the tail, torso and hindlimbs show adaptations similar to those of other aquatic mammals like otters and

pinnipeds Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammal, marine mammals. They comprise the extant taxon, extant family (biology ...

. The dentition was suited to feed on hard-shelled invertebrate prey, such as crustaceans and shellfish. They probably lived along African coastlines. Borths and Stevens (2017.) described a new specimen of ''Apterodon macrognathus'' (among with other hyaenodonts) and concluded that the dental eruption of secondary dentition occurred much more slowly than in

carnivora Carnivora is a Clade, monophyletic order of Placentalia, placental mammals consisting of the most recent common ancestor of all felidae, cat-like and canidae, dog-like animals, and all descendants of that ancestor. Members of this group are f ...

ns.

Phylogeny

The phylogenetic relationships of genus ''Apterodon'' are shown in the following cladogram.

References

Hyaenodonts Eocene mammals of Africa Oligocene mammals of Africa Oligocene mammals of Europe Prehistoric placental genera {{paleo-mammal-stub