Extinct Subspecies of Pleistocene Jaguars (Panthera onca)

The ancestor of the jaguar diverged from ancestral lions and leopards about 8 million years ago.  An extinct species of jaguar (Panthera gombaszoegensis) roamed Eurasia from the early to mid Pleistocene (1.5 million years BP- ~300,000 BP).  This species crossed the Bering Land Bridge over 500,000 years ago and colonized North and South America where it evolved into Panthera onca–the same species still found today from Arizona to Argentina. The jaguar had a much wider range in North America during the late Pleistocene than it does now.  Jaguar bones, dating to this era, have been excavated from sites as far north as Washington state, Oregon, Indiana, West Virginia, and Pennsylvania.  I’ve reviewed the data from these sites in an attempt to determine when jaguars ranged this far north.  I was curious to know if jaguars were able to survive that far north during the coldest climatic phases.  However, these sites are all cave deposits without reliable dating evidence.  Associated faunal remains may be from specimens thousands of years older or younger than the jaguar remains and because climate often fluctuated rapidly during the Pleistocene, they can’t be used as an index for the climatic conditions that occurred when the jaguars lived in the regions.  The ancestor of Panthera onca did negotiate the Bering Land Bridge and Canada to reach its known Pleistocene range.  This region was quite cold even during warmer climate phases, so I believe Pleistocene jaguars were more adaptable to climatic extremes than one might expect.  There’s just not enough evidence to know for sure.

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Both extinct subspecies of Pleistocene jaguars were somewhat larger than present day jaguars.

Pleistocene jaguars were abundant in southeastern North America, rivaling dire wolves (Canis dirus) as the most common large predator in the region then.  Jaguars have been unearthed from at least 18 sites in Florida, 6 sites in Tennessee, 2 sites in Georgia, 1 in South Carolina and another in Alabama.  A jaguar fell into Craighead Caverns in Tennessee and even left paw prints and claw marks in its failed attempt to escape the natural trap.  Complete skeletons of jaguars have been found in other Tennessee caves.  The jaguar that lived in the southeast during the Pleistocene was a distinct subspecies known as Panthera onca augusta.  It was given subspecies status based on its size, averaging 15%-20% larger than the modern jaguar.  Extant jaguars still demonstrate clines (geographical variations in size).  Present day jaguars average larger in the northern and southern limits of their range than they do near the equator.  Larger individuals maintain body heat more efficiently, perhaps explaining the size difference in the cooler parts of their range.  Present day jaguars also grow larger in areas where they can prey on livestock.  So it’s likely the combination of cooler climate and larger prey contributed to the larger size of P. onca augusta during the Pleistocene.

Another extinct subspecies of jaguar lived in South America–P. onca mesembrina.  This population of jaguars also averaged larger than present day jaguars.  A study of P. onca mesembrina genetics determined this clade became extinct in southern Argentina about 12,280 calendar years ago along with other regional megafauna including Darwin’s ground sloth, horse, a llama (Lama gracilis), and a local population of guanacos(Lama guanacoe).  These clades of jaguars and guanacos left no descendents, but other clades of these species recolonized southern Argentina less than 2,000 years later.  The scientists who participated in this study conclude human activities combined with a warming climate phase caused megafauna extinctions here.  Southern beech forests expanded as temperatures and precipitation increased, and the forest encroached on the grasslands.  Herds of grazing animals, forced to migrate greater distances to reach suitable pastures, were more easily ambushed by an increasing human population that now had access to more wild plant foods in the growing forests.  Megafauna survived previous climate changes by altering their patterns of movement throughout the landscape, but some how humans disrupted this during the terminal Pleistocene.

References:

Metcalf, Jessica; et. al.

“Synergistic Role of Climate Warming and Human Occupation in Patagonian Megafaunal Extinctions during the Last Deglaciation”

Science Advances June 2016

Simpson, G.G.

“Discovery of Jaguar Bones and Footprints in a Cave in Tennessee”

American Museum Novitates 1941

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