Simbakubwa

Last updated

Simbakubwa
Temporal range: 23.0–22.0  Ma
O
S
D
C
P
T
J
K
Pg
N
early Miocene
Simbakubwa-kutokaafrika 2.jpg
reconstruction of
Simbakubwa kutokaafrika
Simbakubwa kutokaafrika.jpg
size comparison to human
Scientific classification OOjs UI icon edit-ltr.svg
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]

Contents

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 1,308 and 1,554 kg (2,884 and 3,426 lb), based on equations derived from carnassial length of hyaenodonts and m3 length of felids respectively, 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 kilograms (1,100 lb), [3] though this study estimated the body mass of Megistotherium with a low estimate of 317 kg (699 lb) to higher estimates of 1,794–3,002 kg (3,955–6,618 lb) using the same methods. [1]

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]

Related Research Articles

<i>Thylacoleo</i> Extinct genus of marsupials

Thylacoleo is an extinct genus of carnivorous marsupials that lived in Australia from the late Pliocene to the Late Pleistocene, often known as marsupial lions. They were the largest and last members of the family Thylacoleonidae, occupying the position of apex predator within Australian ecosystems. The largest and last species, Thylacoleo carnifex, approached the weight of a lioness. The estimated average weight for the species ranges from 101 to 130 kg.

<span class="mw-page-title-main">Creodonta</span> Former order of extinct flesh-eating placental mammals

Creodonta is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ancestral to the modern Carnivora, this order is now usually considered a polyphyletic assemblage of two different groups, the oxyaenids and the hyaenodonts, not a natural group. Oxyaenids are first known from the Palaeocene of North America, while hyaenodonts hail from the Palaeocene of Africa.

<i>Megistotherium</i> Hyaenodontid creodont genus from early Miocene epoch

Megistotherium is an extinct genus of hyaenodont belonging to the family Hyainailouridae that lived in Africa.

<i>Megantereon</i> Extinct genus of saber-toothed cat from North America, Eurasia and Africa

Megantereon is an extinct genus of prehistoric machairodontine saber-toothed cat that lived in North America, Eurasia, and Africa from the late Pliocene to the Middle Pleistocene. It is a member of the tribe Smilodontini, and closely related to and possibly the ancestor of the famous American sabertooth Smilodon. In comparison to Smilodon it was somewhat smaller, around the size of a jaguar, though it is thought to have had a similar hunting strategy as an ambush predator.

<i>Epicyon</i> Genus of carnivores

Epicyon is a large, extinct, canid genus of the subfamily Borophaginae, native to North America. Epicyon existed for about 15 million years from the Hemingfordian age of the Early Miocene, to the Hemphillian of the Late Miocene. Epicyon haydeni is the largest known canid of all time, with the type species reaching 2.4 m (7.9 ft) in length, 90 cm (35 in) in shoulder height and approximately 100–125 kg (220–276 lb) in body mass. The largest known humerus specimen belonged to an individual weighing up to 170 kg (370 lb).

<i>Wakaleo</i> Extinct genus of marsupials

Wakaleo is an extinct genus of medium-sized thylacoleonids that lived in Australia in the Late Oligocene and Miocene Epochs.

<i>Ysengrinia</i> Extinct genus of mammals known as bear dogs

Ysengrinia is an extinct genus of carnivoran in the family Amphicyonidae, that lived during the Late Oligocene to Early Miocene. Fossil remains have been discovered in Western Europe, the United States and possibly China. The European species are among the earliest known members of the Thaumastocyoninae, a group of aberrant amphicyonids showcasing hypercarnivorous adations, but are only known from fragmentary remains. The American species is much better preserved and shows a robust, black-bear sized predator. These fossils play an important role in our understanding of the biotic interchange between Eurasia and North America during the earliest Miocene. However, more recent research suggests that the genus might be polyphyletic, and that several of its species should be excluded from Ysengrinia.

<i>Pterodon</i> (mammal) Extinct genus of mammals

Pterodon is an extinct genus of hyaenodont in the family Hyainailouridae, containing five species. The type species Pterodon dasyuroides is known exclusively from the late Eocene to the earliest Oligocene of western Europe. The genus was first erected by the French zoologist Henri Marie Ducrotay de Blainville in 1839, who said that Georges Cuvier presented one of its fossils to a conference in 1828 but died before he could make a formal description of it. It was the second hyaenodont genus with taxonomic validity after Hyaenodon, but this resulted in taxonomic confusion over the validities of the two genera by other taxonomists. Although the taxonomic status of Pterodon was revised during the late 19th and early 20th centuries, it became a wastebasket taxon for other hyaenodont species found in Africa and Asia. Today, only the type species is recognized as belonging to the genus while four others are pending reassessment to other genera.

<i>Hyainailouros</i> Genus of mammals (fossil)

Hyainailouros ("hyena-cat") is an extinct polyphyletic genus of hyaenodont belonging to the family Hyainailouridae that lived during the early to middle Miocene, of which there were at least three species spread across Europe, Africa, and Asia.

<span class="mw-page-title-main">Hyaenodonta</span> Extinct order of mammals

Hyaenodonta is an extinct order of hypercarnivorous placental mammals of clade Pan-Carnivora from mirorder Ferae. Hyaenodonts were important mammalian predators that arose during the early Paleocene in Europe and persisted well into the late Miocene.

<span class="mw-page-title-main">Hyainailouridae</span> Extinct family of mammals

Hyainailouridae ("hyena-cats") is a family of extinct predatory mammals within the superfamily Hyainailouroidea within extinct order Hyaenodonta. Hyaenodontids arose during the middle Eocene and persisted well into the middle Miocene. Fossils of this group have been found in Asia, Africa, North America and Europe.

Isohyaenodon is an extinct polyphyletic genus of hyainailourid hyaenodont mammal from the subfamily Hyainailourinae). Remains are known from early to middle Miocene deposits in Kenya, East Africa.

Exiguodon is an extinct genus of hyainailourid hyaenodont mammal of the subfamily Hyainailourinae. Remains are known from early Miocene deposits in Kenya and Uganda, in East Africa.

<i>Falcatodon</i> Species of extinct mammal

Falcatodon is an extinct genus of hyainailourid hyaenodonts of the subfamily Hyainailourinae, from the Early Oligocene (Rupelian) of the Faiyum Oasis depression in Egypt.

Sectisodon is an extinct genus of hyainailourid hyaenodont mammal of the subfamily Hyainailourinae from early Oligocene to early Miocene deposits in Egypt and Uganda.

<i>Kerberos langebadreae</i> Extinct animal

Kerberos ("Cerberus") is an extinct genus of hyainailourid hyaenodonts in the subfamily Hyainailourinae, that lived in Europe. It contains the single species Kerberos langebadreae.

<span class="mw-page-title-main">Sinopidae</span> Extinct family of mammals

Sinopidae is an extinct family of predatory placental mammals from extinct order Hyaenodonta. Fossil remains of these mammals are known from early to middle Eocene deposits in North America, Europe and Asia.

<span class="mw-page-title-main">Dissopsalini</span> Extinct tribe of mammals

Dissopsalini is an extinct tribe of teratodontid hyaenodonts. Fossil remains of these mammals are known from early to late Miocene deposits in Asia and Africa.

<span class="mw-page-title-main">Hyainailourinae</span> Extinct subfamily of mammals

Hyainailourinae ("hyena-cats") is an extinct subfamily of hyainailourid hyaenodonts that lived in Africa, Asia, North America and Europe from the middle Eocene to middle Miocene. They appeared in Africa about 47.8 Ma ago and soon after spread as far as East Asia.

Myacyon is an extinct genus of large sized carnivoran mammals, belonging to the family Amphicyonidae, that lived in Africa during the Miocene epoch. Due to the limited scope and fragmentary nature of the severely damaged holotype, as well as the illustrations in its descriptions, which have been called inadequate, usage of this genus poses serious issues. However, it is notable for being one of the last surviving members of its family and its adaptions to hypercarnivory. Its relationships to other amphicyonids are obscure, and it is not closely related to Bonisicyon, the other late surviving African genus, although it has been proposed that it descends from a species of Cynelos or Namibiocyon.

References

  1. 1 2 3 4 5 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.
  2. 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.
  3. 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.