''Simbakubwa'' ("great

lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'' native to Africa and India. It has a muscular, broad-chested body; short, rounded head; round ears; and a hairy tuft at the end of its tail. It is sexually dimorphi ...

") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

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 ...

of hyainailourid

hyaenodonts 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 t ...

from

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

subfamily

Hyainailourinae Hyainailourinae ("hyena-cats") is an extinct paraphyletic subfamily of hyainailourid hyaenodonts that lived in Africa, Asia, North America and Europe during the middle Eocene to middle Miocene. Classification and phylogeny Taxonomy * Subfamily: ...

that lived in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

during the early

Miocene The Miocene ( ) is the first 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 means "less recen ...

Etymology

The name of this genus comes from

Swahili language Swahili, also known by its local name , is the native language of the Swahili people, who are found primarily in Tanzania, Kenya and Mozambique (along the East African coast and adjacent litoral islands). It is a Bantu language, though Swahili ...

for "great

". Species name ''Simbakubwa kutokaafrika'' means "great lion of

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 ...

Description

Different

regression model In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one ...

s produce a wide range of body mass estimates for ''Simbakubwa kutokaafrika'': from a low estimate of , comparable to the largest lions, to an upper estimate possibly reaching up to , which would surpass the modern

polar bear The polar bear (''Ursus maritimus'') is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear specie ...

in size. The fossils of ''Simbakubwa'' were first discovered by rural Kenyans at Meswa Bridge, Western Kenya. Thereafter Matthew Borths and Nancy Stevens published the findings after examining the fossils which had been stored at the Nairobi National Museum in Kenya for decades. The type specimen consists of a mandible from the lower jaw, a right upper maxilla and some postcranial remains. The light wear patterns on the dentition indicate that the holotype specimen was a young adult at the time of its death. The study of the postcranial remains indicates ''Simbakubwa'' was possessed of a semi-digitigrade walking stance.

Paleoecology

''Simbakubwa'', like other hyainailourids, probably was a specialist hunter and scavenger that preyed on creatures such as rhinoceroses and early proboscideans. It may have been somewhat less specialized in crushing bone than its later relatives such as ''

Hyainailouros ''Hyainailouros'' (" hyena-cat") is an extinct polyphyletic genus of hyainailourid hyaenodont mammal of the polyphyletic tribe Hyainailourini within paraphyletic subfamily Hyainailourinae, that lived during the early to middle Miocene, of wh ...

''. However, like ''Hyainailouros'', ''Simbakubwa'' possessed lingually rotating

carnassial Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified f ...

blades, ensuring a constant shearing edge throughout its life.

Phylogeny

The phylogenetic relationships of genus ''Simbakubwa'' are shown in the following cladogram:

References

{{Taxonbar, from1=Q63203949, from2=Q63203734 Hyaenodonts Fossil taxa described in 2019 Miocene mammals of Africa Prehistoric placental genera Prehistoric monotypic mammal genera