''Megalictis'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of large predatory

mustelid The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family ...

s that existed in North America during the "

cat gap The cat gap is a period in the fossil record of approximately 25 million to 18.5 million years ago in which there are few fossils of cats or cat-like species found in North America. The cause of the "cat gap" is disputed, but it may have been ca ...

" from the Late

Arikareean The Arikareean North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 30,600,000 to 20,800,000 years BP, a period of . It is usuall ...

(Ar4) 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 ...

epoch. It is thought to have resembled a huge ferret, with a body mass of up to .

History of discovery

The genus ''Megalictis'' was first described by W. D. Matthew in 1907, and assigned to the family

Mustelidae The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in th ...

.Paleobiology Database Two similar genera discovered at the same time, ''Aelurocyon'' (Peterson, 1907) and ''Paroligobunis'' (Peterson, 1910) were identified as synonymous with ''Megalictis'' in 1996Andersson, p.39 though ''Paroligobunis'' was re-established as a separate genus in 1998. P. R. Bjork, in 1970, assigned the genus to the subfamily Mellivorinae, whilst J. A. Baskin reassigned it to

Oligobuninae ''Oligobuninae'' is an extinct subfamily of the family Mustelidae The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among othe ...

in 1998. Three species have been identified in the genus: ''M. ferox'', ''M. petersoni'', and ''M. frazieri'', whilst two more, ''Megalictis brevifacies'' and ''Megalictis simplicidens'', have since been determined to be synonymous with ''M. ferox''. Other synonyms of ''M. ferox'' include ''Aelurocyon brevifacies'', ''Brachypsalis simplicidens'' and ''Paroligobunis simplicidens''. Specimens of ''M. ferox'' have been found at ten sites in

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large porti ...

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...

and

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

, dated to the Harrisonian period - from 24.8 to 20.6 million years ago. The 19 specimens so far identified have a wide range of sizes, which is believed to be evidence of extreme

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

, a phenomenon where males and females of the species will grow to different sizes; a 1996 study rejected the possibility of multiple "morphologically uniform" but differently sized species as unlikely. However, later studies identified significant morphological variation in the joints of the forearms, which would not be consistent with sexual dimorphism. Andersson suggests that the identification of all of these as a single species may need revision.

Description

''Megalictis'' reached the size of a modern jaguar and was one of the largest terrestrial mustelids ever recorded. The skull of ''Megalictis ferox'' was as long as of jaguar but wider, almost as of the

black bear Black bear or Blackbear may refer to: Animals * American black bear (''Ursus americanus''), a North American bear species * Asian black bear (''Ursus thibetanus''), an Asian bear species Music * Black Bear (band), a Canadian First Nations group ...

. It had a powerful bite force, allowing it to crush bones of the large prey, as modern hyenas and jaguars can. ''Megalictis'' surpassed in size other mustelids like '' Ekorus'', '' Eomellivora'', and ''

Plesiogulo ''Plesiogulo'' is a genus of prehistoric carnivore that lived from Miocene to Pliocene of Africa, Eurasia and North America. An ancestral relationship to the wolverine (''Gulo gulo'') was once suggested, but it is no longer considered likely. How ...

''. ''Ekorus ekakeran'', another mustelid of the same period found in Africa, is estimated to have been around . Matthew described it as having short stout legs, with short feet and long non-retractible claws, similar to a modern ferret but about twice the size, and noted that "the teeth indicate an animal fully as predaceous as the wolverine, but the skeleton points to more fossorial habits". Research comparing the joints of the forelegs to modern mammalian carnivores suggests that it waited in ambush and grappled with its prey, rather than hunting it down by pursuit like a modern

cheetah The cheetah (''Acinonyx jubatus'') is a large cat native to Africa and central Iran. It is the fastest land animal, estimated to be capable of running at with the fastest reliably recorded speeds being , and as such has evolved specialized ...

.Hopkin

References

Sources

* * * * * * * * {{Taxonbar, from=Q6808432 Prehistoric mustelids Miocene mustelids Miocene mammals of North America White River Fauna Fossil taxa described in 1907 Prehistoric carnivoran genera