Simbakubwa

Extinct genus of mammals

Simbakubwa Temporal range: 23.0–22.0 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓ early Miocene

reconstruction of Simbakubwa kutokaafrika

size comparison to human
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Hyaenodonta
Superfamily:	†Hyainailouroidea
Family:	†Hyainailouridae
Subfamily:	†Hyainailourinae
Genus:	†Simbakubwa Borths & Stevens, 2019
Type species
†Simbakubwa kutokaafrika Borths & Stevens, 2019

Simbakubwa ("great lion") is an extinct genus of hyaenodonts to the family Hyainailourinae that lived in Kenya during the early Miocene.^[1]

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.^[2] 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 regression models produce a wide range of body mass estimates for Simbakubwa kutokaafrika: from a low estimate of 280 kg (620 lb), 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 1,500 kg (3,300 lb), an equation based on the m3 length of felids, which would surpass the modern polar bear in size.^[1] 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 500 kg.^[3]

The study of the postcranial remains indicates Simbakubwa was possessed of a semi-digitigrade walking stance.^[1]

Paleobiology

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. However, like Hyainailouros, Simbakubwa possessed lingually rotating carnassial blades, ensuring a constant shearing edge throughout its life.^[1]

References

^ ^a ^b ^c ^d Matthew R. Borths; Nancy J. Stevens (2019). "Simbakubwa kutokaafrika, gen. et sp. nov. (Hyainailourinae, Hyaenodonta, 'Creodonta,' Mammalia), a gigantic carnivore from the earliest Miocene of Kenya". Journal of Vertebrate Paleontology. 39 (1): e1570222. Bibcode:2019JVPal..39E0222B. doi:10.1080/02724634.2019.1570222. S2CID 145972918.
^ Zuckerman, C. (18 April 2019). "This new species of ancient carnivore was bigger than a polar bear". National Geographic. Archived from the original on April 18, 2019. Retrieved 2019-04-18.
^ Sorkin, Boris (2008). "A biomechanical constraint on body mass in terrestrial mammalian predators". Lethaia. 41 (4): 333–347. Bibcode:2008Letha..41..333S. doi:10.1111/j.1502-3931.2007.00091.x.

Mammals of clade Pan-Carnivora

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Placentalia
Superorder: Laurasiatheria
Clade: Scrotifera
Grandorder: Ferungulata
Mirorder: Ferae

Pan-Carnivora

Carnivoramorpha	See Carnivoramorpha below ↓
†Hyaenodonta	See Hyaenodonta below ↓
†Oxyaenodonta	See Oxyaenodonta below ↓
†Wyolestidae	†Wyolestes
†Simidectes †Altacreodus †Tinerhodon

†Hyaenodonta

†Hyaenodontoidea

†Hyaenodontidae	†Alienetherium †Boritia †Cartierodon †Consobrinus †Cynohyaenodon †Eurotherium †Hyaenodon †Leonhardtina †Matthodon †Neosinopa †Oxyaenoides †Paenoxyaenoides †Paracynohyaenodon †Praecodens †Preregidens †Prodissopsalis †Propterodon †Protoproviverra †Quercytherium

†Proviverridae

†Allopterodon
†Lesmesodon
†Minimovellentodon
†Morlodon
†Parvagula
†Proviverra

†Afro‑Arabian
clade

†Parvavorodon
†Tritemnodon
†Koholia

†Indohyaenodontidae

†Glibzegdouia
†Indohyaenodon
†Yarshea

†Hyainailouroidea

†Hyainailouridae

†Maocyon/Orienspterodon clade

†Maocyon
†Orienspterodon

†Apterodontinae

†Apterodon
†Quasiapterodon

†Hyainailourinae

†Leakitherium †Megistotherium †Mlanyama †Metapterodon †Pakakali †Paroxyaena †Simbakubwa
†Akhnatenavus clade	†Akhnatenavus †Hemipsalodon †Ischnognathus
†Hyainailourini	†Exiguodon †Falcatodon †Hyainailouros †Parapterodon †Sectisodon †Sivapterodon †Isohyaenodon †Kerberos †Pterodon

†Prionogalidae

†Namasector
†Prionogale
†Thereutherium

†Teratodontinae

†Anasinopa
†Brychotherium
†Buhakia
†Dissopsalis
†Ekweeconfractus
†Furodon
†Kyawdawia
†Masrasector
†Metasinopa
†Paratritemnodon
†Teratodon

other representatives

†Eoproviverra †Gazinocyon †Pyrocyon
†Arfia clade	†Arfia
†Galecyon clade	†Galecyon
†Lahimia clade	†Boualitomus †Lahimia
†Limnocyonidae	†Iridodon †Limnocyon †Oxyaenodon †Prolaena †Prolimnocyon †Thinocyon
†Sinopidae	†Acarictis †Prototomus †Sinopa

ichnotaxa
of Hyaenodonta

†Creodontipus
†Dischidodacylus
†Sarcotherichnus
†Zanclonychopus
†Hyaenodontipus
†Quiritipes
†Sarjeantipes

†Oxyaenodonta

†Oxyaenidae

†Machaeroidinae	†Apataelurus †Diegoaelurus †Isphanatherium †Machaeroides
†Oxyaeninae	†Argillotherium †Dipsalidictis †Malfelis †Oxyaena †Patriofelis †Protopsalis †Sarkastodon
†Palaeonictinae	†Ambloctonus †Dipsalodon †Palaeonictis
†Tytthaeninae	†Tytthaena

Carnivoramorpha

Carnivoraformes
(Clade "A")

Clade "B"

†Messelogale †Miocyon †Simamphicyon †Uintacyon †Xinyuictis †Zodiocyon
†Quercygalidae	†Quercygale
†Gracilocyon/Oodectes clade	†Eogale †Gracilocyon †Oodectes †Paramiacis †Paroodectes

Clade "C"

Clade "D"

†Ceruttia
†Harpalodon
†Lycarion
†Neovulpavus
†Procynodictis
†Prodaphaenus
†Tapocyon
†Walshius

Carnivora
(Clade "E")

Caniformia	(See Caniformia)
Feliformia	(See Feliformia)

other representatives

†Africtis
†Dawsonicyon
†Miacis

ichnotaxa of
Carnivoraformes

†Falcatipes

†Viverravoidea

†Viverravidae

†Orientictis †Pappictidops †Preonictis †Variviverra
†Didymictinae	†Bryanictis †Didymictis †Intyrictis †Pristinictis †Protictis †Raphictis
†Ictidopappinae	†Ictidopappus
†Viverravinae	†Simpsonictis †Viverravus †Viverriscus