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Miracinonyx

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Miracinonyx
Temporal range: Pleistocene
~2.5–0.016 Ma
↓
Artist's rendition of M. trumani
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Feliformia
Family: Felidae
Subfamily: Felinae
Genus: †Miracinonyx
Adams, 1979
Type species
†Crocuta inexpectata
Cope, 1895
Species
  • †M. inexpectatus (Cope, 1895) sensu Adams, 1979
  • †M. trumani (Orr, 1969) sensu Adams, 1979
Synonyms
M. inexpectatus synonymy
  • Crocuta inexpectata Cope, 1895
  • Uncia inexpectata (Cope, 1895) sensu Cope, 1899
  • Felis longricus Brown, 1908
  • Felis concolor Brown, 1908
  • Smilodontopsis mooreheadi Hay, 1922
  • Felis (Puma) inexpectata (Cope, 1895) sensu Simpson, 1941
  • Felis studeri Savage, 1960
  • Acinonyx studeri (Savage, 1960) sensu Kurtén & Anderson, 1980
  • Acinonyx inexpectatus (Cope, 1895) sensu Kurtén & Anderson, 1980
M. trumani synonymy
  • Felis concolor Wilson, 1942
  • Felis trumani Orr, 1969
  • Acinonyx trumani (Orr, 1969) sensu Kurtén & Anderson, 1980

Miracinonyx (colloquially known as the "American cheetah") is an extinct genus of felids belonging to the subfamily Felinae that was endemic to North America from the Pleistocene epoch (about 2.5 million to 16,000 years ago) and morphologically similar to the modern cheetah (Acinonyx jubatus), although its apparent similar ecological niches have been considered questionable due to anatomical morphologies of the former that would have limited the ability to act as a specialized pursuit predator.[1][2] The genus was originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.[3]

The two species commonly identified are M. inexpectatus and M. trumani. Sometimes, a third species, M. studeri, is included, but it is more often listed as a junior synonym of M. inexpectatus. M. inexpectatus ranged from the Blancan to Irvingtonian ages of North America while M. trumani was exclusive to the Rancholabrean age.[1][4]

Discovery and naming

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The first fossils attributed to Miracinonyx were several isolated teeth from Port Kennedy Bone Cave from Pennsylvania, dating back to the Irvingtonian age. The American paleontologist Edward Drinker Cope originally considered these to be related to the spotted hyena, and described the material as Crocuta inexpectata in 1895.[5] However, in 1899 he reclassified the specimens as Uncia inexpectata, considering them closely related to the snow leopard.[6]

More fossil material was recovered from deposits of similar age in Maryland and Arkansas, where in 1941 American paleontologist George Gaylord Simpson found them all belonging to the same animal, one he considered to be more closely related to the cougar (Puma concolor), naming the animal as Felis (Puma) inexpectata.[7]

A second species, Felis studeri, was described by D. E. Savage in 1960 based on a more complete material consisting of extensive postcranial and cranial material of the animal.[8] However, a 1976 review of fossil pumas from Kurtén considered F. inexpectata and F. studeri to be the same species, with F. inexpectata having priority. The other valid species (then as Felis trumani) was described in 1969 by Orr based on a complete skull from the Late Pleistocene found in Crypt Cave, Nevada.[1]

Taxonomy and evolution

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Research into the American cheetah has been contradictory. It was originally believed to be an early cougar representative, before being reclassified in the 1970s as a close relative of the cheetah.[9] This suggested that the ancestors of the cheetah diverged from the Puma lineage in the Americas and migrated back to the Old World, a claim repeated as recently as Johnson et al. (2006),[10] and by Dobrynin et al. (2015)[11] However, other research by Barnett and Faurby, through examining mitochondrial DNA and reanalyzing morphology, has suggested reversing the reclassification: the American cheetah developed cheetah-like characteristics through parallel evolution, but it is most closely related to Puma and not to the modern cheetah of Africa and Asia.[1][12][13] Moreover, Faurby notes that no Acinonyx fossils have been found in North America, and no Miracinonyx fossils elsewhere. However, O'Brien et al. (2016) posit that the supposed homoplasy between the genera is controversial, as it is asserted that is not necessarily any conclusive anatomical or genetic basis for dismissing a homologous relationship between Acinonyx and Miracinonyx.[14] The veracity of the origin of the modern cheetah is also debated; however, Miracinonyx is believed to have evolved from cougar-like ancestors, regardless of whether in the Old World or the New World.[15]

The cougar and M. trumani are believed to have split from a cougar-like ancestor around three million years ago;[12] where M. inexpectatus fits in is unclear, although it is probably a more primitive version of M. trumani.[16]

Below is the phylogeny from Chimento & Dondas (2017) when describing the earliest known fossil record of cougars in South America. As shown here, they found Miracinonyx to be a sister taxon to Puma (though in their paper they considered the former genus to be an extinct subgenus of the latter).[17]

 Felinae 
 †Miracinonyx 
 

†M. inexpectatus

†M. trumani

 Puma 
 

( var. smaller cats )

Adams (1979) found these animals to be intermediates in size and morphology between cheetahs and cougars and decided to place them in their own genus Miracinonyx.[9]

The name is a combination of the Latin mīrus ("wonderful") and Acinonyx, the cheetah family, itself a combination of the Greek ἀκίνητος (akī́nētos) meaning "unmoved" or "motionless" and ὄνυξ (ónyx) meaning "nail" or "hoof".[9]

Description

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It has been proposed that Miracinonyx is an instance of parallel evolution with the cheetah of the Acinonyx genus. Recent studies, however, suggest that it was not as specialized in chasing as the cheetah, as it retained retractable claws and could supinate its forelimbs to grapple with prey, which may have diminished its ability to run fast compared to the true cheetah.[1][18] Instead, it was more closely related to the cougar, and while M. trumani might have employed a hunting behavior without modern analogue, it may not have relied on speed as much as a cheetah. M. trumani also had a brain similar to a cougar's and therefore was not cognitively prepared for the predatory behavior of true cheetahs. Moreover, it had underdeveloped paranasal sinuses which prevents the brain from overheating in Acinonyx during high-speed chases, though this may reflect the colder temperatures of Pleistocene North America compared to Africa and Iran.[19] Additionally, the injuries that led to the death of a sub-adult Miracinonyx according to a 2022 research article by John-Paul Michael Hodnett et al suggest that Miracinonyx felids, like extant cats such as the puma, regularly fought one another; instances of conspecific aggression among Acinonyx cheetahs are relatively rare.[2][4][20] Miracinonyx species were also larger than a modern cheetah and similar in size to a modern North American cougar. The body mass was typically around 70 kg (150 lb), with a head-and-body length of 170 cm (67 in), tail length around 92 cm (36 in), and shoulder height of 85 cm (33 in).[21] Large specimens could have weighed more than 95 kg (209 lb).[22] Miracinonyx most likely preyed on mountain goats (Oreamnus americanus), horses (Equus sp.) and especially pronghorns (Antilocapra americana).

It is often assumed that pronghorns evolved to evade Miracinonyx, but this is still debated. In the Neogene period (or more specifically the Miocene epoch), in North America, grassland environments, especially those of C4 carbon fixations, were replacing forested lands in North America as well as C3 plants, causing extensive changes in vegetational structure. As a result, artiodactyls and perissodactyls generally evolved with hypsodont dentition for eating C4 grasses and distally longer limbs for easier movement within open environments. In comparison, true pursuit predators didn't even exist until the Plio-Pleistocene, a more recent development of carnivorans compared to the ungulates that already were built for speed some 20 million years before.[23][24][25]

Behavior

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Fossils from Arizona show that American cheetahs were territorial animals, with evidence of pathologies being found on some of the bones.[26][27][28]

M. inexpectatus, ranging from the Blancan to Irvingtonian ages, and was more similar to the cougar in build than M. trumani.[4][15] Fossil remains of M. inexpectatus found in Hamilton Cave in West Virginia show that this creature lived with and competed with other large cats like jaguars (Panthera onca) and the saber-toothed cat (Smilodon sp.).[1][29]

M. trumani, exclusive to the Rancholabrean age, was more cursorial and Cheetah-like then M. inexpectatus,[4][15] but unlike cheetahs, both species retained fully retractable claws.[1][2] This genus likely hunted in a way with no modern analogues as its elbow-joint morphology was intermediate between A. jubatus and P. concolor.

Miracinonyx hunted cursorial prey like Antilocapra (such as the modern pronghorn) as well as the extinct Tetrameryx and Stockoceros[30], and horses (Equus sp.), as well as bighorn sheep and mountain goats.[4]

Fossil distribution

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Artist's reconstruction of M. inexpectatus

Fossil remains of Miracinonyx have been found across the United States and as far south as Mexico.[31] Fossils of M. trumani have been found in Arizona,[32][33] New Mexico, Florida, Wyoming,[34] Colorado,[35] Nebraska, South Carolina,[36] Maryland, and Pennsylvania.[37] The most complete finds of M. trumani are from the Natural Trap Cave in northern Wyoming.[38]

Fossils of M. inexpectatus have also been found in Florida,[39][40][41] Texas,[42] Colorado, Georgia,[36] South Carolina,[36][43] Pennsylvania, Maryland,[44] and California.[45][46] In 2022, the skeletal remains of a M. inexpectatus were retrieved from a cave in southwestern Virginia.[47]

References

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  1. ^ a b c d e f g Van Valkenburgh, Blaire; Grady, Frederick; Kurtén, Björn (1990). "The Plio-Pleistocene Cheetah-Like Cat Miracinonyx inexpectatus of North America". Journal of Vertebrate Paleontology. 10 (4): 434–454. Bibcode:1990JVPal..10..434V. doi:10.1080/02724634.1990.10011827. ISSN 0272-4634. JSTOR 4523343.
  2. ^ a b c Figueirido, Borja; Pérez-Ramos, Alejandro; Hotchner, Anthony; Lovelace, David; Pastor, Francisco J.; Martín-Serra, Alberto (2023). "Elbow-joint morphology in the North American 'cheetah-like' cat Miracinonyx trumani". Biology Letters. 19 (1). doi:10.1098/rsbl.2022.0483. PMC 9873470. PMID 36693427.
  3. ^ "Late Pleistocene, paleoecology and large mammal taphonomy, Natural Trap Cave, Wyoming". National Geographic Research & Exploration. 1993. Retrieved 2017-06-20.
  4. ^ a b c d e Michael Hodnett, John Paul; White, Richard S.; Carpenter, Mary C.; Mead, Jim I.; Santucci, Vincent L. (2022). "Miracinonyx Trumani (Carnivora; Felidae) from the Rancholabrean of the Grand Canyon, Arizona and its Implications for the Ecology of the "American Cheetah"". Late Cenozoic Vertebrate Paleontology.
  5. ^ Cope, Edward D. (1895). "The fossil vertebrata from the fissure at Port Kennedy, Pa". Proceedings of the Academy of Natural Sciences of Philadelphia. 47: 446–450. JSTOR 4061990.
  6. ^ Cope, Edward D. (1899). "Vertebrate remains from Port Kennedy bone deposit". Journal of the Academy of Natural Sciences of Philadelphia. 11 (2).
  7. ^ Simpson, George Gaylord (1941). "Large Pleistocene felines of North America" (PDF). American Museum Novitates (1136). The American Museum of Natural History.
  8. ^ Savage, Donald E. (1960). "A Survey of Various Late Cenozoic Vertebrate Faunas of the Panhandle of Texas: Felidae". University of California Press. {{cite journal}}: Cite journal requires |journal= (help)
  9. ^ a b c Adams, Daniel B. (14 September 1979). "The Cheetah: Native American". Science. 205 (4411): 1155–1158. Bibcode:1979Sci...205.1155A. doi:10.1126/science.205.4411.1155. PMID 17735054. S2CID 17951039.
  10. ^ Johnson, W.E.; Eizirik, E.; Pecon-Slattery, J.; Murphy, W.J.; Antunes, A.; Teeling, E.; O'Brien, S.J. (6 January 2006). "The Late Miocene radiation of modern Felidae: A genetic assessment". Science. 311 (5757): 73–77. Bibcode:2006Sci...311...73J. doi:10.1126/science.1122277. PMID 16400146. S2CID 41672825.
  11. ^ Dobrynin, Pavel; Liu, Shiping; Tamazian, Gaik; Xiong, Zijun; Yurchenko, Andrey A.; Krasheninnikova, Ksenia; Kliver, Sergey; Schmidt-Küntzel, Anne; Koepfli, Klaus-Peter (2015-01-01). "Genomic legacy of the African cheetah, Acinonyx jubatus". Genome Biology. 16: 277. doi:10.1186/s13059-015-0837-4. ISSN 1474-7596. PMC 4676127. PMID 26653294.
  12. ^ a b Barnett, Ross; Barnes, Ian; Phillips, Matthew J.; Martin, Larry D.; Harington, C. Richard; Leonard, Jennifer A.; Cooper, Alan (9 August 2005). "Evolution of the extinct sabretooths and the American cheetah-like cat". Current Biology. 15 (15): R589–R590. Bibcode:2005CBio...15.R589B. doi:10.1016/j.cub.2005.07.052. PMID 16085477. S2CID 17665121.
  13. ^ Faurby, S.; Werdelin, L.; Svenning, J.C. (2016-05-05). "The difference between trivial and scientific names: There were never any true cheetahs in North America". Genome Biology. 17: 89. doi:10.1186/s13059-016-0943-y. ISSN 1474-7596. PMC 4858926. PMID 27150269.
  14. ^ O'Brien, Stephen J.; Koepfli, Klaus Peter; Eizirik, Eduardo; Johnson, Warren; Driscoll, Carlos; Antunes, Agostinho; Schmidt-Kuntzel, Anne; Marker, Laurie; Dobrynin, Pavel (2016-01-01). "Response to comment by Faurby, Werdelin and Svenning". Genome Biology. 17: 90. doi:10.1186/s13059-016-0942-z. ISSN 1474-760X. PMC 4858819. PMID 27150130.
  15. ^ a b c Figueirido, Borja; Pérez-Ramos, Alejandro; Hotchner, Anthony; Lovelace, David M.; Pastor, Francisco J.; Palmqvist, Paul (2022-12-22). "The brain of the North American cheetah-like cat Miracinonyx trumani". iScience. 25 (12): 105671. Bibcode:2022iSci...25j5671F. doi:10.1016/j.isci.2022.105671. ISSN 2589-0042. PMC 9758517. PMID 36536677.
  16. ^ Haaramo, Mikko (2005-11-15). "Felinae – small cats". Felidae. Mikko's phylogeny archive. Archived from the original on 2007-03-27. Retrieved 2007-02-20.
  17. ^ Chimento, N.R.; Dondas, A. (2017). "First record of Puma concolor (Mammalia, Felidae) in the Early-Middle Pleistocene of South America". Journal of Mammalian Evolution. 25 (3): 381–389. doi:10.1007/s10914-017-9385-x. S2CID 16249074.
  18. ^ Van Valkenburg, Blaire; Pang, Benison; Cherin, Marco; Rook, Lorenzo (2018). "The Cheetah: The Evolutionary History and Paleoecology". In Marker, Laurie; K. Boast, Lorraine; Schmidt-Kuntzel, Anne (eds.). Cheetahs: Biology and Conservation: Biodiversity of the World: Conservation from Genes to Landscapes. Academic Press. pp. 25–32. ISBN 978-0-12-804120-8.
  19. ^ Figueirido, Borja; Pérez-Ramos, Alejandro; Hotchner, Anthony; Lovelace, David M.; Pastor, Francisco J.; Palmqvist, Paul (2022-12-22). "The brain of the North American cheetah-like cat Miracinonyx trumani". iScience. 25 (12): 105671. doi:10.1016/j.isci.2022.105671. ISSN 2589-0042. PMC 9758517.
  20. ^ Figueirido, Borja; Pérez-Ramos, Alejandro; Hotchner, Anthony; Lovelace, David M.; Pastor, Francisco J.; Palmqvist, Paul (2022). "The brain of the North American cheetah-like cat Miracinonyx trumani". iScience. 25 (12): 105671. Bibcode:2022iSci...25j5671F. doi:10.1016/j.isci.2022.105671. PMC 9758517. PMID 36536677.
  21. ^ "Extinct American Cheetah, Miracinonyx inexpectatus". San Diego Zoo factsheet. July 2010. Archived from the original on 2016-03-04. Retrieved 2013-12-02.
  22. ^ Caro, T.M. (1994). Cheetahs of the Serengeti Plains: Group Living in an Asocial Species. Chicago: University of Chicago Press. p. 500. ISBN 978-0-226-09433-5.
  23. ^ Croft, Darin A.; Lorente, Malena (2021-08-17). "No evidence for parallel evolution of cursorial limb adaptations among Neogene South American native ungulates (SANUs)". PLOS ONE. 16 (8): e0256371. doi:10.1371/journal.pone.0256371. ISSN 1932-6203. PMC 8370646. PMID 34403434.
  24. ^ Janis, Christine M.; Wilhelm, Patricia Brady (1993-06-01). "Were there mammalian pursuit predators in the tertiary? Dances with wolf avatars". Journal of Mammalian Evolution. 1 (2): 103–125. doi:10.1007/BF01041590. ISSN 1573-7055.
  25. ^ Figueirido, Borja; Pérez-Ramos, Alejandro; Hotchner, Anthony; Lovelace, David; Pastor, Francisco J.; Martín-Serra, Alberto (January 2023). "Elbow-joint morphology in the North American 'cheetah-like' cat Miracinonyx trumani". Biology Letters. 19 (1). doi:10.1098/rsbl.2022.0483. ISSN 1744-957X. PMC 9873470. PMID 36693427.
  26. ^ Pappas, Stephanie (2022-05-25). "20,000 years ago, two American cheetahs fought to the death in a Grand Canyon cave". livescience.com. Retrieved 2023-02-13.
  27. ^ "The big cat scan: modern radiology meets an extinct American cheetah". news.wisc.edu. Retrieved 2023-02-13.
  28. ^ "Earth Notes: Ancient Cheetahs in the Grand Canyon". KNAU Arizona Public Radio. 2022-06-22. Retrieved 2023-02-13.
  29. ^ The microtine rodents of the Cheetah Room fauna, Hamilton Cave, West Virginia, and the spontaneous origin of Synaptomys (Report). 1988. doi:10.3133/b1853.
  30. ^ Higgins, Pennilyn; Meachen, Julie; Lovelace, David (2023-02-20). "Were pronghorns (Antilocapra) primary prey for North American cheetahs (Miracinonyx)?". Quaternary International. Natural Trap Cave, Wyoming, U.S.A. Records a Detailed Faunal, Floral, aDNA, Isotopic, and Geologic Record of the Late Quaternary. 647–648: 81–87. Bibcode:2023QuInt.647...81H. doi:10.1016/j.quaint.2022.08.003. ISSN 1040-6182. S2CID 251700435.
  31. ^ Miller, W.E.; Carranza-Castañeda, O. (1984). "Late Cenozoic mammals from central Mexico". Journal of Vertebrate Paleontology. 4 (2): 216–236. Bibcode:1984JVPal...4..216M. doi:10.1080/02724634.1984.10012005.
  32. ^ "American Cheetah Fossil (U.S. National Park Service)". www.nps.gov. Retrieved 2021-09-13.
  33. ^ editor., Baskin, Jon A., editor. Czaplewski, Nicholas J., editor. Lucas, Spencer G., editor. McDonald, H. Gregory (Hugh Gregory), 1951- editor. Mead, Jim I., editor. White, Richard S. Jr., editor. Lichtig, Asher J. (2022). Late Cenozoic vertebrates from the American Southwest: a tribute to Arthur H. Harris. New Mexico Museum of Natural History and Science. OCLC 1350541559. {{cite book}}: |last= has generic name (help)CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  34. ^ Martin, L.D.; Gilbert, B.M.; Adams, D.B. (1977). "A Cheetah-Like Cat in the North American Pleistocene". Science. 195 (4282): 981–982. Bibcode:1977Sci...195..981M. doi:10.1126/science.195.4282.981. PMID 17735673. S2CID 38895439.
  35. ^ Emslie, S.D. (1986). "Late Pleistocene vertebrates from Gunnison County, Colorado". Journal of Paleontology. 60 (1): 170–176. Bibcode:1986JPal...60..170E. doi:10.1017/s0022336000021612. S2CID 129010079.
  36. ^ a b c Sanders, A.E. (2002). "Additions to the Pleistocene Mammal Faunas of South Carolina, North Carolina, and Georgia". Transactions of the American Philosophical Society. 92 (5): i. doi:10.2307/4144916. JSTOR 4144916.
  37. ^ Autin, B. "LibGuides: Extinct American Cheetahs (Miracinonyx spp.) Fact Sheet: Distribution & Habitat". ielc.libguides.com. Retrieved 2021-08-29.
  38. ^ Wang, X.; Martin, L. (1993). "Late Pleistocene, paleoecology and large mammal taphonomy, Natural Trap Cave, Wyoming". National Geographic Research & Exploration. 9: 422–435.
  39. ^ Scott, M.; Gary, S. (1987). Late Pliocene (Late Blancan) vertebrates from the St. Petersburg Times site, Pinellas County, Florida, with a brief review of Florida Blancan faunas. Florida Paleontological Society. OCLC 182860777.
  40. ^ Simpson, G.G. (1929). Pleistocene mammalian fauna of the Seminole Field, Pinellas County, Florida. American Museum of Natural History. OCLC 729432.
  41. ^ Martin, R. A. (1969). Fossil mammals of the coleman ILA local fauna, Sumter County, Florida. [s.n.] doi:10.5962/bhl.title.39853.
  42. ^ Slaughter, B.H. (1966). "The Moore Pit Local Fauna; Pleistocene of Texas". Journal of Paleontology. 40 (1): 78–91. JSTOR 1301775.
  43. ^ Kohn, M.J.; McKay, M.P.; Knight, J.L. (2005). "Dining in the Pleistocene—Who's on the menu?". Geology. 33 (8): 649–652. doi:10.1130/g21476ar.1. S2CID 55786870.
  44. ^ Gidley, J.W. (1913). "Preliminary report on a recently discovered Pleistocene cave deposit near Cumberland, Maryland". Proceedings of the United States National Museum. 46 (2014): 93–102. doi:10.5479/si.00963801.46-2014.93.
  45. ^ "Fossil history of the panther (Puma concolor) and the cheetah-like cat (Miracinonyx inexpectatus) in Florida". ufdc.ufl.edu. Retrieved 2021-08-25.
  46. ^ Trayler, Robin B.; Dundas, Robert G.; Fox-Dobbs, Kena; Van De Water, Peter K. (2015-11-01). "Inland California during the Pleistocene—Megafaunal stable isotope records reveal new paleoecological and paleoenvironmental insights". Palaeogeography, Palaeoclimatology, Palaeoecology. 437: 132–140. Bibcode:2015PPP...437..132T. doi:10.1016/j.palaeo.2015.07.034. ISSN 0031-0182.
  47. ^ Wade, S. (2022). "Caving team discovers, retrieves rare ice age-era cat skeleton from Southwest Virginia cave". Cardinal News. Retrieved 2022-01-26.
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