Simbakubwa ("great lion") is an extinct genus of Hyaenodonta to the family Hyainailourinae that lived in Kenya during the Early Miocene.
Discovery and Etymology
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 name of this genus comes from the Swahili language, meaning "great lion". The species name Simbakubwa kutokaafrika means "great lion of Africa”.
Description
Different
produce a wide range of body mass estimates for
Simbakubwa kutokaafrika: from a low estimate of , based on an equation derived from the m3 length of various large carnivorans, comparable to the largest lions, to an upper estimate possibly reaching up to , based on equations derived from carnassial length of hyaenodonts and m3 length of felids respectively, which would surpass the modern
polar bear in size.
However, hyainailourids possessed proportionally very large heads in comparison to their body, and postcranial remains indicate that the similar sized
Hyainailouros was about the size of a tiger, whereas the larger
Megistotherium has been estimated to have reached a maximum weight of ,
though this study estimated the body mass of
Megistotherium with a low estimate of to higher estimates of using the same methods.
The study of the postcranial remains indicates Simbakubwa was possessed of a Digitigrade walking stance.
Paleobiology
Simbakubwa, like other hyainailourids, probably was a specialist hunter and
scavenger that preyed on creatures such as
Rhinoceros and early
Proboscidea. It may have been somewhat less specialized in crushing bone than its later relatives such as
Hyainailouros. However, like
Hyainailouros,
Simbakubwa possessed lingually rotating
carnassial blades, ensuring a constant shearing edge throughout its life.
