An Anatomical Comparison Between the Extinct North American Cheetahs (Miracynonyx sp.) and the Late Pleistocene/Holocene Cougar (Puma concolor)

One of my readers recently asked whether the cougar (Puma concolor) might be the same species as the extinct North American cheetahs (Miracynonyx inexpectatus and M. trumani).  This is not as ridiculous a question as a layman might think because paleontologists often mistakenly identify multiple species from fossil remains that after re-evaluation are eventually determined to be from 1 species.  I love reading articles about vertebrate paleontology, but I usually skip over anatomical descriptions because they are pretty dry.  But to answer his question, I used google to search for a paper comparing the anatomical differences between Puma and Miracynonyx.  I did not find a journal article with a comprehensive anatomical comparison between the 2, but I did recall a paper I’d already read that discussed some of the differences.  I’ve linked the paper below in  my references.

Cougars and North American cheetahs had different-sized teeth.  Cougars have larger canines and lower molars than North American cheetahs, but they have smaller lower premolars (p4) and smaller upper pre-molars (P3).  They also have a “less reduced protocone on upper premolar P4.”  North American cheetahs had longer limbs than cougars as the below photos from the linked paper show.  So the answer is no.  Cougars were definitely not the same species as the North American cheetahs.

Fossil history of the panther (Puma concolor) and the cheetah-like cat (Miracinonyx inexpectatus) in Florida - Page 208

Comparison of limb bones between cougar and North American cheetah shows the latter had longer hind foot bones and were better runners.

Fossil history of the panther (Puma concolor) and the cheetah-like cat (Miracinonyx inexpectatus) in Florida - Page 210

North American cheetahs had longer front foot bones as well.

Cougars and North Americans cheetahs are closely related, however.  Genetic evidence suggests their shared lineage originated 6-8 million years ago, and a puma-like cat, probably Puma pardoides, crossed the Bering Land Bridge from Asia shortly after this.  In North America the puma-like ancestor diverged into 3 lines: cougars, North American cheetahs, and jaguarundis. The Puma genus diverged from Miracynonyx about 3.2 million years ago.

The fossil evidence shows M. inexpectatus  lived all across North America from the late Pliocene to the middle Pleistocene (~3 million years BP-~300,000 years BP).  In the Florida Museum of Natural History there are 47 records in state of M. inexpectatus at sites thought to date from the Pliocene to the mid-Pleistocene, but they are known from just 1 late Pleistocene site in Florida.  This site is named Lecanto 2A. The only other Late Pleistocene site with a possible M. inexpecatus  fossil (1 leg bone) is in Cavetown, Maryland.  These specimens can’t be radio-carbon dated.  The reason the specimen from Lecanto 2A is considered Late Pleistocene is its association with specimens of other species known from this age including dire wolf, Florida spectacled bear, rice rat, and cotton rat.  It’s possible there were relic populations of M. inexpectatus  still living during the Late Pleistocene, but it seems more likely it’s a case of older fossils getting mixed with younger fossils.

M. inexpectatus  expanded its range at a time coinciding with the expansion of grassland habitat.  Its long legs helped it run down prey.  M. trumani was even more adapted for living in open habitat.  This species appeared during the Late Pleistocene and was restricted to western North America as far as we know from the fossil record.  M. trumani is probably a descendent of M. inexpecatus which had intermediate characteristics between cougars and M. trumani. 

The paleobiology database indicates cougar fossils dating to the Early and Mid Pleistocene in California, Idaho, Washington, and Mexico have been reported.  Nevertheless, cougar fossils predating the Late Pleistocene are rare.  In the Florida Museum of Natural History there are 44 records of cougar from the Late Pleistocene but just 2 from the Mid Pleistocene and 2 from the Early Pleistocene.  The early Pleistocene specimens are referred to as Puma lacrustis, but I searched for this scientific name on google and found nothing, so I’m not sure what these specimens actually were.  Genetic evidence suggests cougars were well established in South America between 300,000 years BP-200,000 years BP, and this corresponds with the widespread fossil evidence of this species throughout North America during this time period.  I hypothesize cougars began to expand their range widely during an early Rancholabrean interglacial from a regional ancestral population undetected in the fossil record.  This time period would correspond to when forested conditions expanded.  Cougars are ambush predators that prefer forests and woodlands.

North American cheetahs are not as closely related to Old World cheetahs as previously thought.  Physical similarities between the 2 are just another example of convergent evolution.

References:

Barnett, Ross; et. al.

“Evolution of the Extinct Sabretooth and the American Cheetah-like Cat”

Current Biology 15 (5) August 2005

Culver, M.; W. Johnson, J. Pecon-Slattery, and S. O’Brien

“Genomic Ancestry of the American Puma (Puma concolor)

Journal of Heredity 91 (3) 2009

Morgan, Gary and Kevin Seymour

“Fossil History of the Panther (Puma concolor)  and the Cheetah-like Cat (Miracynonxy inexpectatus) in Florida”

Bulletin of the Florida Museum of Natural History 1997

http://ufdc.ufl.edu/UF00095787/00001/1j

 

 

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One Response to “An Anatomical Comparison Between the Extinct North American Cheetahs (Miracynonyx sp.) and the Late Pleistocene/Holocene Cougar (Puma concolor)”

  1. Leopardus amnicola and More Additional Specimens of Cenozoic Fauna from South Carolina | GeorgiaBeforePeople Says:

    […] in size with small pseudo-cheetahs.  I covered this topic on a previous blog entry.  (See: https://markgelbart.wordpress.com/2018/05/28/an-anatomical-comparison-between-the-extinct-north-amer… ) Edisto Beach abounds with subfossil remains of big cats including saber-tooths, giant lions, […]

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