Nimravides

This article is about the extinct saber-toothed cat Nimravides. For the similarly named "false" saber-toothed cat, see Nimravus.

Nimravides Temporal range: Late Miocene (Clarendonian to Hemphillian), 11–6.5  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
N. catocopis skull, American Museum of Natural History
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Suborder:	Feliformia
Family:	Felidae
Subfamily:	† Machairodontinae
Tribe:	† Homotherini
Genus:	† Nimravides Kitts 1958
Type species
Nimravides thinobates (Macdonald, 1948)
Other Species
N. catocopis(Cope, 1887) N. pedionomus(MacDonald, 1948) N. hibbardi(Dalquest, 1969) N. galianiBaskin, 1981
Synonyms
N. catocopis Machaerodus catacopsisCope, 1887 Machairodus catacopsis Nimravides catacopsis Nimravides catocopsis(misspelling) Machairodus lahayishupupOrcutt and Calede, 2021 Nimravides catocopis lahayishupup N. thinobates Pseudaelurus thinobatesMacDonald, 1948 N. pedionomus Pseudaelurus pedionomus N. hibbardi Pseudaelurus hibbardi

Nimravides is a genus of extinct saber-toothed cats that was endemic in North America during the Late Miocene, from 11 to 6.5 Ma. ^[1] Despite its scientific name, Nimravides does not belong to the Nimravidae, but is a true cat belonging to the family Felidae. ^[2]

Taxonomy

The genus Nimravides was originally described by Kitt in 1958 for the species "Pseudaelurus" thinobates. ^[3] In 1969, Dalquest described the species Pseudaelurus hibbardi. ^[4] The species Machaerodus catocopis was described by Cope in 1887, based on a partial mandible from the Loup Fork Beds. ^[5] The species Pseudaelurus thinobates and Pseudaelurus pedionomus were both described by James Reid MacDonald in 1948. ^{[6] [7]}

Skull cast of N. galiani, Florida Museum of Natural History

In 1975, Martin and Schultz reassigned Machairodus catacopsis to Nimravides and suggested that N. thinobates was a junior synonym of the former species. ^[8] The species N. galiani was first described in 1981 based on fragmentary material from the Love Bone Beds in Florida. The same paper also described additional fossils of N. thinobates compared to the holotype of N. catacopsis, and concluded that N. catacopsis was best considered a nomen vanum and the material assigned to it should be considered N. thinobates. ^[9]

"Pseudaelurus" pedionomus was reassigned to Nimravides in 1990 by Beaumont. ^[10] In 2003, Tom Rothwell reassigned Pseudaelurus hibbardi to Nimravides. ^[11] And in 2010 it was suggested that N. hibbardi was a junior synonym of Adelphailurus kansensis. ^[12] In 2013, Mauricio Anton et al. suggested that N. catacopsis should be re-reassigned back to Machairodus. ^[13] But this was refuted in 2022 by Jiangzuo et al. and also assigned M. lahayishupup to N. catocopis, considering it as a local subspecies due to its dental difference being a intraspecific variation based on the large sample. ^[1]

Description

Nimravides catocopis, the largest and latest species, was quite large, measuring 100 cm (1.0 m) at the shoulder and was similar in size to a large tiger. It was also possessed of long, powerful legs and a long back. ^[14] Based on mandibular and dental sizes, this species was slightly larger than M. aphantistus on average. Hh2 populations of N. catocopis grew rather large, with two large femurs, presumably males, reaching lengths similar to the American lion. ^[1] The supposed subspecies N. catocopis lahayishupup was also quite large; fossil humerus bones measuring 18 in (46 cm)attributed to the species suggest that this cat was far larger than a modern lion, which has a 13 in (33 cm) humerus. It is estimated to have weighed between 241 and 348 kg, with a mean weight of 277 kg; one particularly large specimen was estimated to weigh 410 kg. ^[15]

Paleobiology

Predatory Behavior

N. catocopis lahayishupup (Previously considered M. lahayishpup) may have preferred prey that typically weigh 413-1,386.3 kg with the maximum prey size being 1.6 tonnes, although it may not have been a large prey specialist. ^[16]

Paleoecology

N. catocopis lahayishupup is found is Hemphillian rocks from Chalk Hills Formation, Rattlesnake Formation, McKay Formation, and Ogallala Formation. ^[17] Within those formations, it coexisted with other Miocene animals such as Teleoceras fossiger , Indarctos oregonensis , and Hemiauchenia vera . It would've would have most likely preyed on the large animals that it lived alongside, which included rhinoceroses, and Hemiauchenia . ^{[18] [19]}

Due to its rarity and different habitat preferences, Amphimachairodous likely didn’t outcompete Nimravides, instead faunal turnover during the Hemphillian stage was the likely cause of their extinction. ^[1]

References

1. Jiangzuo, Qigao; Li, Shijie; Deng, Tao (2022). "Parallelism and lineage replacement of the late Miocene scimitar-toothed cats from the old and New World" (PDF). iScience. 25 (12): 105637. Bibcode:2022iSci...25j5637J. doi:10.1016/j.isci.2022.105637. PMC   9730133 . PMID   36505925.
2. Larry D.Martin (1998). Felidae in Evolution of Tertiary Mammals of North America, Volume 1: Terrestrial Carnivores, Ungulates, Ungulatelike Mammals. Cambridge University Press.
3. Kitts, David B. (1958). "Nimravides, a New Genus of Felidae from the Pliocene of California, Texas and Oklahoma". Journal of Mammalogy. 39 (3): 368–375. doi:10.2307/1376145. JSTOR   1376145.
4. Dalquest, W. W. (1969). "Pliocene carnivores of the Coffee Ranch (type Hemphill) local fauna" (PDF). Bulletin of the Texas Memorial Museum. 15: 1–44.
5. Cope, Edward Drinker (1887). "A saber-tooth tiger from the Loup Fork Beds". The American Naturalist. 21 (11): 1019–1020.
6. MacDonald, James Reid (1948). "The Pliocene carnivores of the Black Hawk Ranch". University of California Publications, Bulletin of the Department of Geological Sciences. 28: 53–80.
7. MacDonald, James Reid (1948). "A new species of Pseudaelurus from the lower Pliocene of Nebraska". University of California Publications, Bulletin of the Department of Geological Sciences. 28: 45–52.
8. Martin, Larry D.; Schultz, C. Bertrand (1975). "Scimitar-toothed Cats, Machairodus and Nimravides, from the Pliocene of Kansas and Nebraska". Bulletin of the University of Nebraska State Museum. 10.
9. Baskin, Jon A. (1981). "Barbourofelis (Nimravidae) and Nimravides (Felidae), with a Description of Two New Species from the Late Miocene of Florida". Journal of Mammalogy. 62 (1): 122–139. doi:10.2307/1380483. JSTOR   1380483.
10. Beaumont, G. (1990). "Contribution à l'étude du genre Nimravides Kitts (Mammalia, Carnivora, Felidae). L'espèce N. pedionomus (Macdonald)" [Contribution to the study of the genus Nimravides Kitts (Mammalia, Carnivora, Felidae). The species N. pedionomus (Macdonald)]. Archives des Sciences, Genève (in French). 43 (1): 125–157. doi:10.5169/seals-740122.
11. Rothwell, Tom (2003). "Phylogentic systematics of North American Pseudaelurus (Carnivora: Felidae)". American Museum Novitates (3403): 1–64. doi:10.1206/0003-0082(2003)403<0001:PSONAP>2.0.CO;2. S2CID   67753626.
12. Hodnett, John-Paul (2010). "A Machairodont felid (Mammalia; Carnivora; Felidae) from the latest Hemphillian (Late Miocene/Early Pliocene) Bidahochi Formation, northeastern Arizona". Paleobios. 29 (3). doi: 10.5070/P9293021800 .
13. Antón, Mauricio; Salesa, Manuel J.; Siliceo, Gema (2013). "Machairodont Adaptations and Affinities of the Holarctic Late Miocene Homotherin Machairodus (Mammalia, Carnivora, Felidae): The Case of Machairodus Catocopis Cope, 1887". Journal of Vertebrate Paleontology. 33 (5): 1202–1213. Bibcode:2013JVPal..33.1202A. doi:10.1080/02724634.2013.760468. JSTOR   42568635. S2CID   86067845.
14. Antón, Mauricio (2013). Sabertooth. Bloomington, Indiana: University of Indiana Press. p. 123. ISBN   9780253010421.
15. Orcutt, John D.; Calede, Jonathan J.M. (2021). "Quantitative Analyses of Feliform Humeri Reveal the Existence of a Very Large Cat in North America During the Miocene". Journal of Mammalian Evolution. 28 (3): 729–751. doi:10.1007/s10914-021-09540-1. S2CID   235541255.
16. Orcutt, John D.; Calede, Jonathan J.M. (2021). "Quantitative Analyses of Feliform Humeri Reveal the Existence of a Very Large Cat in North America During the Miocene". Journal of Mammalian Evolution. 28 (3): 729–751. doi:10.1007/s10914-021-09540-1. S2CID   235541255.
17. Orcutt, John D.; Calede, Jonathan J.M. (2021). "Quantitative Analyses of Feliform Humeri Reveal the Existence of a Very Large Cat in North America During the Miocene". Journal of Mammalian Evolution. 28 (3): 729–751. doi:10.1007/s10914-021-09540-1. S2CID   235541255.
18. Marie Morales (May 5, 2021). "Sabre-Toothed Cat From 9 Million Years Ago Could Take Down Prey 10 Times Its Size". The Science Times . Retrieved May 9, 2021.
19. David Nield (8 May 2021). "Newly Identified Species of Saber-Toothed Cat Was So Big It Hunted Rhinos in America". ScienceAlert . Retrieved 9 May 2021.