''Ekorus ekakeran'' is a large, extinct

mustelid The Mustelidae (; from Latin , weasel) are a diverse family of carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the suborde ...

mammal. Fossils, including largely complete skeletons, are known from the late

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 ...

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

Description

''Ekorus'' reached almost , comparably to a

wolf The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been recognized, includin ...

and much bigger than the modern

honey badger The honey badger (''Mellivora capensis''), also known as the ratel ( or ), is a mammal widely distributed across Africa, Southwest Asia, and the Indian subcontinent. It is the only living species in both the genus ''Mellivora'' and the subfami ...

(''

Mellivora capensis The honey badger (''Mellivora capensis''), also known as the ratel ( or ), is a mammal widely distributed across Africa, Southwest Asia, and the Indian subcontinent. It is the only living species in both the genus ''Mellivora'' and the subfami ...

''). Standing tall at the shoulders, its build was not similar to that of modern mustelids. Small, modern-day weasels have short legs and can only achieve short bursts of speed. Living large mustelids are either aquatic predators (the otters, Lutrinae), or terrestrial animals with a crouching stance and heavy limbs with adaptations for digging (the

wolverine The wolverine ( , ; ''Gulo gulo''), also called the carcajou or quickhatch (from East Cree, ''kwiihkwahaacheew''), is the largest land-dwelling species, member of the family Mustelidae. It is a muscular carnivore and a solitary animal. The w ...

, and various groups called

badger Badgers are medium-sized short-legged omnivores in the superfamily Musteloidea. Badgers are a polyphyletic rather than a natural taxonomic grouping, being united by their squat bodies and adaptions for fossorial activity rather than by the ...

s). ''Ekorus'' is a representative of an extinct ecological type of mustelid – large stalking and running mammals comparable to

dogs The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers ...

cats The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

hyena Hyenas or hyaenas ( ; from Ancient Greek , ) are feliform carnivoran mammals belonging to the family Hyaenidae (). With just four extant species (each in its own genus), it is the fifth-smallest family in the order Carnivora and one of the sma ...

s, and

amphicyonids Amphicyonidae is an extinct family of terrestrial carnivorans belonging to the suborder Caniformia. They first appeared in North America in the middle Eocene (around 45 mya), spread to Europe by the late Eocene (35 mya), and further spread to Asi ...

. The legs of ''Ekorus'' are built like those of leopards. The face is short, with a felid-like tooth pattern; ''Ekorus'' was a

hypercarnivore A hypercarnivore is an animal that has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant exampl ...

. Analysis of the elbow indicates that it was a strong runner, like modern hyenas and dogs, and did not grapple with its paws, as bears and raccoons do. The legs are long; the feet are short and stout. Fossils of giant Miocene mustelids with similar morphology, reconstructed as hypercarnivores or carnivore-scavengers, have also been discovered in North America,

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, and

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, as well as other parts of

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Paleoecology

Apparently before the African savannas evolved, the giant mustelid ''Ekorus'' stalked its prey, such as the three-toed horse '' Eurygnathohippus'' and the large pig '' Nyanzachoerus'', in forests and woodlands. In the early Cenozoic, Africa was isolated from Eurasia, where modern African groups such as cats and giraffes first evolved. African predators and prey developed along their own lines to hunt in closed environments. ''Ekorus'' had the upright stance typical of active hunters, lacked digging adaptations, and was leopard-sized, with leopard-like body proportions. Since leopards are ambush hunters in forests and woodlands, ''Ekorus'' may have filled a parallel role in the Miocene forests of Africa. Other research has suggested the genus was cursorial, chasing down prey more like a modern

spotted hyena The spotted hyena (''Crocuta crocuta''), also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus ''Crocuta'', native to sub-Saharan Africa. It is listed as being of least concern by the IUC ...

. In general, Miocene predators show larger body sizes with anatomies between the modern "dog-like" pursuit running and "cat-like" stalk-pounce-and-grapple strategies. This was suggested to be the result of the great abundance of prey species in Miocene forests, which allowed predators to survive without having to specialize as either fast runners or grapplers.

Extinction

Felids Felidae ( ) is the family of mammals in the order Carnivora colloquially referred to as cats. A member of this family is also called a felid ( ). The 41 extant Felidae species exhibit the greatest diversity in fur patterns of all terrestria ...

are first recorded on the continent in the early Miocene, in north Africa. Tectonic changes starting about 35 million years ago led to the formation of the

Great Rift Valley The Great Rift Valley () is a series of contiguous geographic depressions, approximately 6,000 or in total length, the definition varying between sources, that runs from the southern Turkish Hatay Province in Asia, through the Red Sea, to Moz ...

, and the rise of highlands that cause

rain shadow A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from body of water, bodies of water (such as oceans and larg ...

s in the surrounding region. Before the rift opened,

was more forested. Grasslands began to spread across Africa in the mid-Miocene, slowly replacing closed forest environments with open savannas. Any or all of these factors may have led to the replacement of ''Ekorus'' and other large mustelid hunters by modern felids, hyaenids, and canids.

References

{{taxonbar, from=Q2258308 Prehistoric mustelids Miocene mammals of Africa Miocene carnivorans Fossil taxa described in 2003 Monotypic prehistoric carnivoran genera