Miomachairodus

Miomachairodus is an extinct genus of large machairodontine (saber-toothed cat) containing only a single species, Miomachairodus pseudailuroides. It is mainly known from Middle Miocene-age fossils in Turkey and persisted until the early Late Miocene (Vallesian).^[1] Fossils of this machairodont have been found in the Vallesian-age Bahe Formation in Shaanxi, China, and Yeni Eskihisar in Anatolia. This Turkish site is of Miocene age and is well known for its pollen studies.^[2]

Miomachairodus Temporal range: Middle Miocene–Late Miocene PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Suborder:	Feliformia
Family:	Felidae
Subfamily:	†Machairodontinae
Genus:	†Miomachairodus Schmidt-Kittler, 1976
Type species
Miomachairodus pseudailuroides Schmidt-Kittler, 1976

History and naming

The genus was first named by paleontologist Norbert Schmidt-Kittler in 1976 based on the holotype, a partial skull from Akçaköy, Eşme District, Turkey, and a second specimen, a lower jaw from Yeni Eskihisar. The generic name Miomachairodus is a combination of Mio, referring to the Miocene when it lived, and Machairodus; the specific name pseudailuroides means "like Pseudaelurus".^[3]

In 2022, material from the Guanigou fauna in the Linxia Basin was described as Miomachairodus sp., and the authors suggested that it represented a new species of Miomachairodus. The fossil, a partial maxilla from the early Late Miocene (early Bahean), represented the oldest known machairodontine in Asia. They refrained from definitively naming the species because it lacked the fourth premolar.^[4] The fossil material had previously been assigned to Machairodus palanderi in 2013.^[5]

Description

The Miomachairodus sp. from the Linxia Basin is known only from a single fossil (HMV2039), a partial maxilla with the first, second, and third incisors, the canine, and the third premolar present, as well as the alveolus of the second premolar and a broken fourth premolar. The incisors are small and the canine tooth has "distinct but small" serrations. It was distinguished from M. pseudailuroides by having a shorter diastema between the canine and third premolar, and in the differing morphology of the third premolar. The describing paper estimated it was a large carnivoran that weighed more than 100 kilograms (220 lb).^[4]

Classification

A 2018 phylogenetic analysis recovered Miomachairodus pseudailuroides as basal to most of the rest of Machairodontinae.^[6]

Machairodontinae	Homotheriini Smilodontini Metailurini Miomachairodus pseudailuroides Diamantofelis ferox Namafelis minor Pseudaelurus spp. Hyperailurictis spp. + Nimravides spp.

References

1. Qiu, Z. (1990). "The Chinese Neogene Mammalian Biochronology — Its Correlation with the European Neogene Mammalian Zonation". In Lindsay, H.E.; Fahlbusch, V.; Mein, P. (eds.). European Neogene Mammal Chronology. Plenum Press. pp. 527–556. doi:10.1007/978-1-4899-2513-8_32.
2. Fortelius, Mikael. Geology and paleontology of the Miocene Sinap Formation, Turkey.
3. Schmidt-Kittler, Norbert (1976). "Raubtiere aus dem Jungtertiär Kleinasiens" [Carnivores from the Late Tertiary of Asia Minor]. Palaeontographica Abteilung A (in German). 155: 107–113.
4. Jiangzuo, Qigao; Wang, Shiqi; Deng, Tao (2023). "Chronological framework and palaeoecology of Carnivora from the Linxia Basin, China". Palaeogeography, Palaeoclimatology, Palaeoecology. 615: 111463. Bibcode:2023PPP...61511463J. doi:10.1016/j.palaeo.2023.111463. S2CID 257061069.
5. Deng, T., Hou, S. K., Xie, G. P., Wang, S. Q., Shi, Q. Q., Chen, S. K., ... & Lu, X. K. (2013). "Chronostratigraphic subdivision and correlation of the Upper Miocene of the Linxia Basin in Gansu, China". Journal of Stratigraphy. 37: 417–427.{{cite journal}}: CS1 maint: multiple names: authors list (link)
6. Piras, Paolo; Silvestro, Daniele; Carotenuto, Francesco; Castiglione, Silvia; Kotsakis, Anastassios; Maiorino, Leonardo; Melchionna, Marina; Mondanaro, Alessandro; Sansalone, Gabriele; Serio, Carmela; Vero, Veronica Anna; Raia, Pasquale (2018). "Evolution of the sabertooth mandible: A deadly ecomorphological specialization". Palaeogeography, Palaeoclimatology, Palaeoecology. 496: 166–174. Bibcode:2018PPP...496..166P. doi:10.1016/j.palaeo.2018.01.034. hdl:2158/1268434.

Further reading

• Viranta, S.; Werdelin, L. (2003). "Carnivora". In Fortelius M.; Kappelman J.; Sen S.; Bernor R. (eds.). Geology and Paleontology of the Miocene Sinap Formation, Turkey. New York: Columbia University Press. pp. 178–193.
• Viranta, S.; Werdelin, L. (1999). Fossil remains of a primitive sabertooth cat (Miomachairodus pseudailuroides) from Anatolia (Abstr.) Abstracts of 79th Annual Meeting, American Society of Mammalogists.