Posts Tagged ‘Panthera atrox’

Panthera atrox: the 1007 Pound Giant Lion

January 31, 2017

An extinct species of lion ( Panthera atrox ), similar but larger than the extant African lion ( P. leo ), occupied open habitat in North America from California to South Carolina and Florida for over 300,000 years.  The American lion evolved from the also extinct Eurasian cave lion ( P. spelea ) when the ice sheet that covered Canada isolated the 2 populations from each other. The 2 species never re-connected during interglacials because extensive spruce forests, an unfavorable habitat for lions, grew between them.  Fossil evidence of large carnivores is relatively uncommon because their populations are smaller than those of their prey. But there are 2 fossil sites that preserved a considerable number of carnivores due to unusual circumstances, and scientists were able to collect enough lion specimens from them to study and compare the anatomy of the species as a whole.  The 2 sites are Natural Trap Cave in Wyoming and the Rancho La Brea Tar Pits in California. Scientists estimated average body size and the results were astounding.

Image result for 1000 pound liger

Hercules is the world’s largest cat. It is a 922 pound lion x tiger hybrid that lives at the Myrtle Beach Safari Preserve in South Carolina.  It is smaller than the estimated size of the largest known fossil specimen of North American lion, an extinct species that formerly lived coast to coast.

The largest male Panthera atrox specimen came from an animal that was estimated to weigh 1007 pounds, though the average male weighed 544 pounds.  The largest female American lion was estimated to weight 577 pounds, while the average was 390 pounds.  By contrast the average extant African male lion weighs 392 pounds.  This means the average female American lion was about the size of the average male African lion.  The large difference in size between the sexes, known as sexual dimorphism, suggests American lions lived in social prides like their African cousins.  An 1000 thousand pound lion would be too large and slow to hunt successfully enough to sustain its bulk, but instead relied on the smaller more agile females to secure all the bison, horses, and camels he required.  A large pride could probably even take down a full grown mammoth.

The large size of the males helped them fend off other male lions that wished to usurp their mating rights and kill their offspring.  The enormous powerful males could also aid in protecting the pride’s kills from competing carnivores such as bears, saber-tooth cats, and dire wolves.  American lions had longer legs and bigger braincases than African lions, so they were faster runners and smarter as well.  P. atrox really was a king of the beasts.


Wheeler, H.T; and G.T. Jefferson

Panthera atrox: Body Proportions, Size, Sexual Dimorphism, and Behavior of the Cursorial Lion of the North American Plains.”

In Papers on Geology, Vertebrate Paleontology, and Biostratigraphy in Honor of Michael O. Woodburne edited by L.B. Albright III

Museum of Northern Arizona Bulletin 65

A New Study of Pleistocene Lion (Panthera spelaea) Genetics Confirms it was a Distinct Species

August 29, 2016

A couple of my readers brought 2 new studies of lion genetics to my attention.  One of the studies confirms the notion that the extinct Eurasian lion (Panthera spelaea) was a distinct species from the present day African lion (Panthera leo).  (See: ) The scientists who co-authored this study analyzed the DNA from 2 ~30,000 year old specimens of “cave” lions and used it to compare with the DNA of other felid species.  They extracted the DNA from a lion arm bone found in Yukon, Canada and some lion hair preserved in Siberian permafrost.  The study suggests Panthera spelaea and P. leo were sister species that diverged ~1.89 million years ago.  This divergence precedes the oldest known lion fossil by over 1 million years.  Panthera fossilis, an extinct archaic species of lion, was thought to be ancestral to both P. spelaea and P. leo.  However, this species lived 700,000 years ago, and the divergence likely occurred before P. fossilis evolved.  Fossils of a cat in the panthera genus that date to 3.5 million years ago have been found in Africa, but not enough skeletal evidence exists to narrow it down to species level.  P. spelaea certainly evolved a greater physiological adaptation to colder climates at the beginning of the Pleistocene as periodic Ice Ages became more severe in Eurasia.  This physiological difference may explain the speciation event that separated P. spelaea from P. leo.

Although this study didn’t examine Panthera atrox, the species of lion that occurred across North America south of the Cordilleran Glacier, the results do make it seem more likely that it too was a different species.

Specimens used in the below referenced study–a lion arm bone found in the Yukon and a hair sample found in Siberian permafrost.

The other study looked at the genetics of present day lions living in Africa and India.  This study determined there are 6 distinct regional breeding populations of lions–the west, central, northwest, northeast and south Asian, east/southern, and southwest.  These breeding populations have been repeatedly isolated from each other because of altered landscapes influenced by cyclical Pleistocene climate changes.  Lions prefer open savannah habitats but avoid thick tropical jungles and large deserts.  A belt of monsoons currently brings heavy rain to west central Africa, but this monsoon belt shifts every ~21,000 years, changing the zones of tropical forests and deserts.  Populations of lions become isolated from each other when their favored savannah habitat fragments and is separated by forest and desert.  Other species of savannah habitat show similar intraspecific genetic isolation including giraffe, water buffalo, bushbuck, waterbuck, hartebeest, warthog, cheetah, and spotted hyena.

The common ancestor of all present day clades of African lion diverged ~245,000 years ago.  The genetic evidence suggests all clades of lions were relegated to small refugia during the Last Glacial Maximum when much of Africa hosted landscapes unsuitable for the big cats.  Humans have recently translocated lions from different regions into other regions in an attempt to rebuild populations.  This interference results in the crossbreeding of different clades with each other.  Zoo lions are also crossbred clades for the most part.


Barnett, Ross; et. al.

“Mitogenetics of the Extinct Cave Lion, Panthera spelaea, Resolve its Position Within the Panthera Cats”

Open Quaternary June 2016

Bertoli, L.S.; et. al.

“Philogeographic Pattern in Africa and High Resolution Delineation of Genetic Codes in the Lion (Panthera leo)

Scientific Reports May 2015


UF9076–A Complete Skull and Jaws of a Giant Lion (Panthera atrox) Found in the Ichetucknee River, Florida

January 7, 2016

A little over 50 years ago, a lucky fossil hunter found the complete skull and jaws of a giant lion in the Ichetucknee River.  This remarkable specimen was missing just a few teeth.  One can imagine how exciting the moment of discovery was for the person who found it.  This particular skull is from a large male lion, and it is larger than almost every lion skull ever excavated from the La Brea Tar Pits in California.  The specimen belongs to the University of Florida Museum of Natural History, and the catalogue number is UF9076.

Overview map of Ichetucknee Spring

Location of Ichetucknee Spring State Park.  The Ichetucknee River flows through this state park into the Santa Fe River where giant lion specimens have also been found.

The Pleistocene Felidae of Florida - Page 222

This is a skull of Panthera atrox found in Florida.  The genus name has been changed since the article in the above photo was published. Fossils of this species are rare in southeastern North America.

The type (or first) specimen of Panthera atrox was found in Mississippi during the 19th century.  For decades scientists debated whether this extinct Pleistocene species was a lion or tiger, but after skulls of big cats were readily available for comparison, paleontologists concluded Panthera atrox was a species of lion.  Until recently it was considered a subspecies of the extant lion still found in Africa and the Gir Forest of India.  But genetic studies suggest there were 3 distinct species of lions during the Pleistocene–the African lion (Panthera leo), the Eurasian “cave” lion (P. spelaea), and the American lion (P. atrox).  P. spelaea also ranged into Beringia north of the Ice Sheet that covered Canada while P. atrox occurred all across North America south of the Ice Sheet.  I don’t like referring to P. spelaea as a cave lion because most individuals never entered a cave in their lives.  They are called cave lions because that is where their remains were most commonly preserved.  These lions should not be confused with the cougar (Puma concolor), also referred to as the mountain “lion.”  Puma concolor is much smaller and not a closely related species.

Panthera atrox was on average 25% larger than extant African lions, and it had a larger brain.  Large males weighed up to 600 pounds.  Some scientists believe it was a solitary predator, unlike its living cousin.  They cite the lack of manes on paintings of lions in European caves.  The manes are evidence of male competition for mates within a social system.  However, some of the cave illustrations depict groups of lions.  There is no way of knowing for sure, but I lean toward the likelihood that Panthera atrox did live in prides because its closest living relative does.

Since the discovery of UF9076, specimens of Panthera atrox have been discovered at 20 other sites in Florida including the Santa Fe River, Vero Beach, the Gulf of Mexico (parts of which were above sea level during Ice Ages), Monkey Jungle Hammock, Cutler Hammock, St. Petersburg, Peace River, Lecanto, Waccasassa River, and Steinhatchee.  These are scattered throughout the state.  The jaw fragment with 2 attached teeth of a Panthera atrox was also found at Edisto Beach, South Carolina. (From measurements of the teeth, trained paleontologists determined it was from a small female lion.  The size slightly exceeds that of the largest jaguar distinguishing it from that species.  I’m not 100 % confident in this diagnosis, but I’ll defer to the experts.)  The presence of Panthera atrox at all of these sites indicates it occurred throughout southeastern North America during the late Pleistocene.

Panthera atrox co-occurred with jaguars (Panthera onca augusta) in North America but are less common in the fossil record of the east.  Jaguars prefer forested wet environments; extant lions inhabit more open plains, so one may assume P. atrox also preferred  open habitats.  Jaguars are probably more common in the fossil record because forested environments prevailed over open habitats in the southeast.  Nevertheless, the presence of P. atrox does suggest some extensive prairie and savannah habitat existed in the south.  They preyed on grazing bison and horses here.  Lions wandering through forests between pockets of savannah likely encountered jaguars and vice-versa.  Both species overlapped and competed with saber-tooths (Smilodon fatalis), scimitar-tooths (Dinobastis serum) cougars, dire wolves (Canis dirus), possibly doles (Cuon alpinus), and various kinds of bears.  What a curious ecological competition.

One final note: If P. atrox did prefer drier more open habitat, they would’ve been less likely to become preserved.  They died in the open, their bodies destroyed by the ravages of an unprotected environment.  By contrast jaguars like water and their remains would’ve been more likely preserved in watery springs and sinkholes.  Perhaps P. atrox was more common in the south than the fossil record indicates.

See also:





Homo sapiens is the Only Evil Species

January 21, 2013

Humans bestowed the scientific name of Panthera atrox upon the extinct Pleistocene lion that used to live in North America.  The Latin word, atrox, means terrible, cruel, horror.  How arrogant and unfair for the only truly evil species to ever walk the earth to refer to another species as a terrible cruel horror.  Sure, other species besides man commit violent acts such as cannibalism, fratricide, and the killing of young sired by another male.  But these behaviors follow the rules of surivival of the fittest.  They are examples of animal behavior shaped by evolution.  Man, however, is the only species that murders and commits other despicable acts for reasons not based on activities necessary for survival.

The animal that comes closest to matching the evil of Homo sapiens is our closest living relative–Pan troglodytes, also known as the chimpanzee.  They fight intertribal wars, and occasionally kill members of their own tribes, including infants.  Upon further contemplation, these behaviors still fall within the rules of survival of the fittest.  Chimp wars are fought over natural resources, and murdering fellow troop members may solve disputes over hierarchy–again another Darwinian survival advantage.  Even ants, which are practically pre-programmed automatons, fight wars.  So I can’t really convince myself that chimpanzees are an evil species.

Man is the only species that commits mass genocide, even when resources are not scarce.  Throughout history, genocides have never followed the evolutionary rules of survival of the fittest, nor have they been based on any kind of rational thought.  Tyrants have never ordered the killings of thousands or millions of people because they were afraid they or their biological kin were in danger of starving to death.   The fight over natural resources explains, if not justifies, human wars, but there is no evolutionary explanation for genocide.  Genocide is simply used to terrorize a population, oftentimes so an egomaniac can maintain political control.  But egomaniacs are well aware that they could survive and reproduce as an individual without ever becoming a famous tyrant.  The people who aid the tyrant also know killing mass numbers of people is not necessary for their own well being and reproduction.

Victims of the Nazis–a mass grave of Jews.  No other species devotes so much energy to genocide.  Survival of the human species doesn’t require genocide.  It’s difficult to explain the evolutionary advantage of genocide.

The German people were heavily criticized after World War II for their role in the Holocaust which would have never been possible without their cooperation.  Germans convicted of war crimes claimed they were merely following orders.  Stanley Milgram, a Jewish psychologist, wondered if all humans had a tendency to submit to authority, even if it meant performing acts they knew were morally wrong.  So he designed a now famous experiment: A person was told to administer shocks to an unseen subject who could be heard.  The subject was actually an actor who was not really given electric shocks.  An authority figure (an alleged professor) gently urged the person to continue adminstering increasing levels of electrical shock, while the actor went from expressing mild discomfort to groans to screams to begging for the experiment to stop because of his heart condition to silence and assumed unconciousness or death.  Prior to this experiment, Milgram polled psychologists on what they thought the results would be.  Psychologists thought on average that only 3% of participants would continue shocking the subject til the silence implied he might have died.  The results were shocking–66% completed the experiment, though many showed signs of stress, as if they knew what they were doing was wrong.  This experiment has been repeated numerous times with similar results, most recently on a Discovery Channel special entitled “How Evil Are You?” that aired in 2011.  The experiment shows that an authority figure can influence most people to endanger and kill other people.  All it takes is a little gentle prodding.

A bizarre incident highlights this evil element that makes up part of what is known as humanity.  A man posing as a police officer used an untraceable disposable phone to call a McDonalds in Mt. Washington, Kentucky and convince the manager to strip search an employee in a backroom because she had allegedly stolen money from a customer’s purse.  Eventually, he convinced her to call her boyfriend to watch over the poor, naked, teenaged girl.  While the manager went back to work, the perverted creep convinced the manager’s boyfriend to severely spank the employee’s naked butt, then ordered the girl to give the man a blowjob.  Both complied.  A security camera captured the whole episode as seen in this youtube clip from an episode of 20/20.

The creep on the phone was a Florida prison guard named David Stewart.  Police eventually caught him but not before he (and possibly others) made over 100 similar calls.  The manager was sentenced to 1 year probation; her boyfriend received a 5 year prison sentence.  The victim sued McDonalds and won a $6 million lawsuit, later settled out of court for a lesser amount.  McDonald’s was negligent because they were aware of similar calls and had failed to alert their employees of the perverted hoax.

No other animal is capable of such evil.  A man destroyed other people’s lives because it gave him sexual satisfaction.  And people were too weak-willed to simply hang up the telephone.

This incident was recently dramatized in the movie Compliance.  Test audiences at the initial screening of Compliance unfairly accused the producer of misogyny and exploitation.  The makers of the movie were merely showing a truth about the human condition.  Outraged audience members missed the whole point of the movie.  They should save their ire for all of humanity.

Dramatic portrayal from the movie Compliance based on a real life event that occurred when a pervert on a telephone convinced a store manager and her boyfriend to strip search, spank, and rape an employee.

Logical Flaws in Studies of Pleistocene Carnivore Tooth Wear

January 17, 2013

Van Valkenburgh co-authored a study comparing rates of broken teeth suffered by large modern carnivores with those experienced by fossil carnivores excavated from the Rancho La Brean tar pits.

She found that large carnivores from the La Brean tar pits suffered 3 times as many broken teeth as modern day carnivores.  The fossils she examined from the pits included saber-tooth (Smilodon fatalis), American lion (Panthera atrox), cougars (Puma concolor), bobcats (Lynx rufus), dire wolves (Canis dirus), and coyotes (Canis latrans).  The modern species that she compared them to were lions, jaguars, leopards, cheetahs, bobcats, timber wolves, hyenas, and African hunting dogs.  The specimens from the tar pits dated to between ~36,000 BP-~12,000 BP.  She concluded that competition for prey was more fierce then than it is among modern large carnivores.  She believed increased competition for food forced large carnivores to utilize more of the carcass, and this led to more broken teeth from gnawing on bone.  She dismissed the alternate explanation that the higher rates of broken teeth among large Pleistocene carnivores were the result of attempting to take down larger prey than modern carnivores usually attack.  Dr. Valkenburgh suggested the larger size of the Pleistocene carnivores compensated for the larger size of the prey.

I never paid much attention to this study because using rates of durophagy as a proxy for carnivore competition seemed like a dubious assumption.  (Durophagy is just a fancy word for bone-eating.)  I think different species either eat more bone than other species because they have different nutritional needs, or they eat more for some other unknown reason that has nothing to do with competition.

Last year, a new study was published that completely contradicts Dr. Valkenburgh’s study.

Several scientists looked at teeth from Rancho La Brean predators and extant carnivores using Dental Microwear Textural Analysis (DMTA).  DMTA requires a lot of fancy equipment and procedures including a white light confocal profilometer, a scale sensitive fractal analysis, and a scanning electron microscope.  The scientists are able to see the teeth on a computer screen in 3D.  This eliminates observer measurement error.  Carnivores that avoid bone, such as cheetahs and lions, have different types of microwear on their teeth than those that eat a lot of bone, such as African hunting dogs and hyenas.

This is the equipment used to look at tooth wear in animals.

These scientists found little difference in rates of durophagy between the extinct and extant carnivores, meaning the competition between predators in the late Pleistocene in this region was no more or less fierce than that of today’s Africa.  Of course, I don’t buy the whole proxy assumption in the first place.  Most of the broken teeth were canines rather than molars.  Canines are more likely to break when taking down prey; molars are more likely to break when chewing bones, therefore they conclude the larger size of prey was the factor that explains the higher incidence of broken teeth among large Pleistocene carnivores.

One of the conclusions of this more recent study has a logical flaw.  The scientists authoring this 2nd study used DMTA to look at the teeth of Smilodon and Panthera atrox over time.  Different tar pits hold fossils of different spans of time ranging from ~36,000 BP-~12,000 BP, so they looked at 5 specimens of each species from pits of chronologically different ages.  They found no difference in tooth wear between the older specimens and the young specimens that dated closer to the time of extinction.  Many scientists think large Pleistocene carnivores became extinct because the animals they preyed upon became extinct.   They expected evidence of increased durophagy among the most recent saber-tooths and lions as they were forced to utilize more of the carcass.  But they found no evidence of this.  I think this doesn’t disprove the likelihood that carnivores did die out because their prey disappeared.  The final sentence in the abstract seems to imply that it does though.  It states : “The difference in DMTA attributes from older to younger deposits offers little evidence that declining prey resources were a primary cause of extinction for these large cats.”  Brian Switek, who writes an online blog for National Geographic, discussed this study and even goes so far as to ask what caused the extinctions of large Pleistocene carnivores, as if this study somehow disproves declining populations of suitable prey was the cause.  In my opinion this is flawed thinking.  Besides the dubious assumption that certain species of carnivores utilize more bone if prey is scarce, it seems unreasonable to expect to find the last nutritionally-stressed members of a population to be represented in the fossil record.  The odds of an animal becoming fossilized is so rare that it’s extremely unlikely that a member of the last remnant of a species headed for extinction would become fossilized.  The sample size–just 5–is also way too insignificant to detect whether or not this was occurring.  Moreover, big cats that eat mostly meat and organs and avoid bone are more likely to die of starvation before they chew on many bones.

I contacted the main author of this study, Dr. Larisa Desantis, and pointed out the logical flaws of this conclusion but she never responded.  I tried to comment on Brian Switek’s blog but he wouldn’t even allow my comment to be published.

I believe competition with humans drove saber-tooths and American lions to extinction.  Humans directly hunted them and overhunted their prey, and it was this combination that made it impossible for these species to survive.  To expect to find evidence of this by looking at a handful of fossil teeth under a microscope is ridiculous.

Pleistocene Fossil Felid Ratios from the University of Florida Database

January 16, 2012

I followed the same procedure from last week’s study but counted the number of cat fossils in the University of Florida’s Natural History Museum database instead of dog fossils.  I only counted fossils dating from the Rancholabrean Land Mammal Age 300,000 BP-11,000 BP.  The results may be off a little because I was scrolling down while looking at a computer screen.  The results may also be misleading because many specimens may come from just 1 individual.   Nevertheless, I think the data reveals a good estimate of the ratio of species composition during the Pleistocene.

Listed on the University of Florida Museum of Natural History database, I counted 46 jaguar (Panthera onca) specimens, 21 giant panther (Panthera atrox) specimens, 42 saber-tooth (Smilodon fatalis) specimens, 6 scimitar-tooth (Dinobastis serum) specimens, 41 cougar (Puma concolor) specimens, 46 bobcat (Lynx rufus) specimens, 12 river cat (Leopardus amnicola or weidii) specimens and 1 ocelot (Leopardus pardalis) specimen.

The results are similar to those reported by the amateur fossil collectors who post on the fossil forum.  The most significant difference between their reports and database information is abundance of jaguar to saber-tooth abundance.  Amateur fossil collectors claim jaguar fossils are much more common in Florida than saber-tooth, though they do collect the latter and some have found scimitar-tooth specimens as well which are rare in the database.  It may be that the UF database includes a skeleton of a saber-tooth accounting for multiple specimens from 1 individual.

Dire wolves accounted for 64 specimens in my previous study, making them 33% more common, at least in the fossil record than any single species of big cat.  Overall, big cats combined outnumbered dire wolves 156 to 64, making large felines more than twice as common as dire wolves.  Perhaps there was less competition among species of canids, but more among felids.

Pleistocene habitats favorable to various species of big and small cats varied widely.  Mesic oak forests and cypress swamps, which expanded during warm interglacials and interstadials, favored jaguars, river cats, and ocelots.  Jaguars are adabtable enough to live in desertlike brush conditions which were common during cold arid stadials.  Cougars and bobcats thrive in many different types of environments.  The exact environments favored by giant panthers, saber-tooths, and scimitar-tooths is unknown, but it’s likely they were capable of adapting to many different ecotones.

Saber-tooths were evidently one of the most common large carnivores south of the ice sheets in North America.  They were actually no larger than a modern day jaguar.  Saber-tooths never colonized Eurasia, but a distant cousin, the scimitar-tooth had close relatives that did live from the southern tip of Africa to Alaska.  Scimitar-tooths also had longer front legs but these were more slender than those of the saber-tooth.  Their fangs were also smaller and more curved.  In Africa, Asia, and Europe scimitar-tooths became extinct much earlier than saber-tooths did in America.  I suspect they never learned to fear man, explaining their earlier extinction.  I suggest fanged cats didn’t often back down from anything.  Scimitar-tooths probably colonized southeastern North America during stadials when grasslands expanded due to dry climate which in turn caused an increase in the populations of ungulates. 

Giant panthers probably resembled large maneless lions.  True lions did live in Alaska and across Eurasia.  But south of the ice sheets in North America, the common ancestor split into 2 different species–Panthera atrox and Panthera onca.

8 cat 10 Biggest Cats in the History

This image comparing Pleistocene jaguars with modern jaguars may be a slight exaggeration, but jaguars did grow bigger during the Pleistocene because they preyed on larger mammals and had more competition among carnivores.

I’ll write more about the presence of margays and ocelots in Pleistocene Florida in my next blog entry.

Here are some related articles about big cats from my archives.

“Panthera atrox! What Kind of Cat was it?”–

“Why did fanged cat have sloping backs and large forelimbs?”–

“Two new studies of saber-tooths.”–

“Cougars vs. jaguars”–

Errors in Georgia Before People: Land of the saber-tooths, mastodons, vampire bats, and other strange creatures

January 14, 2011

“To error is human; to forgive divine.”

I tried very hard to write a perfect book with no factual mistakes, typos, or bad grammar.  I’m not a scientist nor a well known writer.  Moreover, my book is self-published.  So I was doubly motivated to produce a flawless product.  I could’ve paid a professional editor to go over my book, but they cost at least $500–more money than I actually expect to make from publishing this book.  And even after paying such a fee, the book could still have mistakes because editors are not Gods.  (As a self-published author, it always delights me to find typos and misspellings in books produced by big book publishers.  I know that’s a shameful attitude.)  Anyway, I didn’t write the book, and I don’t write this blog for money–I write about this subject matter because I love it.  The link below is for my book on amazon.

I was hoping a photo of my book would appear when I cut and pasted the link.  Most of my book sales have been from  I only make $1.31 when my book sells on amazon.  Amazon and Lulu publishers get the rest.  I make a very small piece of the pie.  Incidentally, you can get the book cheaper directly from me.  I charge $24 which includes shipping for a signed copy.  You can get an electronic copy of the book from for just $3.

Since I published my book, I’ve become aware of 3 errors in it.  I’m sure there are more.  Readers, please let me know of any.  Just write a response to this blog entry, and I’ll note it.

The first error is my portrayal of Panthera atrox, formerly Panthera leo atrox, as an animal behaving exactly like an African lion in my chapter recounting an imaginary journey through what’s now Augusta, Georgia 20,000 BP.   Approximately the same time I wrote my book, a scientist was thoroughly studying the anatomy of this species, and he determined it was not a lion, but rather an extinct distinct species within the Panthera genus.  It was a kind of giant panther with a skull like a lion but with a jaw like a jaguar.  I discuss this paper in a July blog entry entitled “Panthera atrox.  What kind of cat was it?”   I was unaware of this study at the time I wrote my book.  Given this new information, I believe it unlikely this giant extinct panther was a social cat, though I’m certain it did battle packs of dire wolves over prey.  I imagine it was less successful in conflicts with dire wolves than a pride of lions would’ve been.

The second error I blame on my carelessness.  I wrote, rewrote, and edited the entire book countless times, yet I goofed in one instance and garbled a whole sentence.  (How this happened, I’ll never know.)  In my chapter recounting an imaginary journey through what’s now Georgia 13,000 BP, I describe a group of paleo-Indian boys practicing their skills with primitive weapons.  On page 181 the first sentence should read “the oldest boy takes his turn” rather than “the oldest boy makes him sturn.”

The third error is the only one that embarrasses me.  In my section on cougars (Puma concolor) I mistakenly wrote that Charlie Killmaster is the hunter who killed a cougar in Georgia in 2008.  Actually, the name of the hunter from my source is never given.  Charlie Killmaster was the Department of Natural Resources employee who documented the event.  The reason this mistake embarrasses me is because I sent a free copy of my book to Rob Pavey, the outdoor editor of the Augusta Chronicle.  He wrote the article I used as my source.  Oh well, I flubbed that one.


I have one more comment.  I posted a few excerpts from my book on one of my favorite websites–the Fossil Forum.  An unfavorable critic there suggested that I shouldn’t give up my day job.  This reveals a misleading belief some people have of the writing profession.  For every John Grisham or Stephen King, there are hundreds, if not thousands of published writers, who can’t afford to give up their day jobs.  Most published writers are English professors or journalists who must continue to work their day jobs, even after they publish their book in order to put food on the table.  ($1.31 doesn’t go far these days, even if multiplied by a 100.)  We don’t write for money; we write because we love the subject we’re writing about.


For next week’s blog entry I hope to write about the extinct giant chipmunk–Tamias aristus.  And I’ll have a complete list of species discovered from the Ladds fossil site and Arredondo IIA.

Panthera atrox! What Kind of Cat was it?

July 28, 2010

One of the biggest cats to ever stalk the world roamed across North America during the Pleistocene.  Panthera atrox, weighing up to 500 pounds and possibly more, was a giant in the genus that includes lions, tigers, jaguars, and leopards.  It fed upon the bison and horses and camels that grazed the Ice Age grasslands and woodlands.  Atrox is a Latin word, meaning cruel, though it’s an error for humans to attach our emotions to an animal that merely did what it needed to do to survive.  Nevertheless, I pity any poor animal caught in the clutches of this powerful predator.

The first fossil specimen of this species was discovered in Mississippi in 1850, and its discovery immediately caused scientific controversy.  Some thought the skull resembled that of a tiger; others thought it was a lion’s skull.  By 1930 scientists had learned how to determine the difference between lion and tiger skulls.  It seems the sutures on the foreheads of the two species are quite different.  Moreover, tigers have noticeably longer nasals.  And from a view of the top of the skull, lion nostrils are visible because their skulls are more elongated, whereas those of the tiger can’t be seen from that angle.  Because Panthera atrox‘s skull closely resembled that of the lion, scientists determined that’s what it was.  Now, a new study using statistics based on data from detailed measurements of lion, tiger, jaguar, and atrox skulls and jaws, has upended the line of reasoning that assumed Panthera atrox was a lion.

The jaw bone of Panthera atrox most closely matches that of the jaguar, though it’s not an exact match, just like the skull of atrox most closely resembles that of the lion but is larger and more elongate in shape, and so is not an exact match of that species either.  So what was it?  The authors of the study referenced below measured every part of the skulls and jaws from 23 atrox fossils, 78 tigers, 126 lions, and 57 jaguars.  They then did a statistical analysis of the results and found that despite deviations between individual specimens of each species, all the measurements clustered into 4 groups, corresponding to each of the 4 species–strong evidence that Panthera atrox was indeed a distinct species.

Though this study surprises me, it makes sense because fossils of Panthera atrox are on average consistently 25% larger than anatomical specimens from extant lions.

Fossils of Panthera atrox are relatively common in western fossil sites, but they’ve also been found in Florida, and South Carolina in addition to the original type specimen discovered in Mississippi.  Undoubtedly, it occurred in Georgia.  True lions did live north of the ice sheet in what today is Alaska, but jaguars and Panthera atrox never advanced above the Cordilleran and Laurentide glaciers that covered what is now Canada.

The scientists who authored this recent study conclude that both Panthera atrox and jaguars descended from a Pliocene-age cat known as Panthera gombaszoengis which is sometimes referred to as a Eurasian jaguar.  This species colonized North America at the beginning of the Pliocene and different populations split into different species: some inhabiting forests evolved into jaguars, same living in open prairies evolved into Panthera atrox, which heretofore on this blog, I’ll refer to as the giant panther.

I believe genetic studies will eventually support this study.

The giant panther had a larger brain than lions and probably was more intelligent, making them a successful large predator, able to kill large game without the help of others of their species.

Because the giant panther is not as closely related to lions as formerly thought, it’s unlikely to have lived in prides.  Instead, like the vast majority of cat species, it survived as a solitary predator and competed with dire wolves and saber-tooths over the many large ungulate species then extant.  Throw in the mighty scavenging short-faced bear (Arctodus simus) and battles galore must have been the norm during Pleistocene dinnertimes.


Christiansen, Per; and John Harris

“Craniomandibular morphology and phylogenetic affinities of Panthera atrox: Implications for evolution and paliobiology of the lion lineage.”

Journal of Vertebrate Zoology 29 (3) 934-945 September 2009

Note: Perhaps the giant panther looked like these jaguar/lion hybrids, though I guess they had a tawny coat, possibly lightly spotted.

Fossiling in Florida by Mark Renz

May 20, 2010

The best chapter in Fossiling in Florida: A Guide for Diggers and Divers by Mark Renz is the one called Prehistoric Portraits–33 pages of nice black and white photographs of fossils that a fossil hunter would likely find in Florida and other southern states.  This makes the book a handy indispensible reference.  Its arrival in my mail box was timely–next week I’m going on an actual fossil-hunting expedition to the low country of South Carolina.  I found a site there readily accessible to the public where late Rancholabrean fossils (over 30 species) have turned up, mixed in with Pliocene-aged marine fossils and shark’s teeth.  In next week’s blog entry I’ll have lots of interesting photographs, hopefully of some specimens I discover myself.

Now back to the book.

Mr. Renz snorkles the backwaters of Florida’s alluvial fossiliferous deposits, feeling his way through sediment that is much richer in prehistoric treasure than that of most other states in North America.  His accounts of avoiding alligators and speeding boats, while searching for fossils, are some of the most entertaining parts of the book.  His wife’s sketches also add to the charm of this work.

One of the reasons I bought the book was because I thought it was self-published, and I wanted to see how another non-academic, self-published author tackled a similar subject to that of my book.  I didn’t know the University of Florida Press published this book.  I found his website–  He has two other books: Megalodon: Hunting the Hunter and Giants in the Storm.  Those must be the ones he self-published.  I’ll have to check those out too.  The cover for the latter looks outstanding.

Anyway, stay tuned for next week’s blog entry.  I’m really looking forward to the upcoming rare opportunity to find some fossils.


This week, I’ve been obsessed with a new paper I came across that was published last fall.  (I’ve only read the abstract.) Two scientists did a thorough study of Panthera leo atrox skulls.  They determined that the North American lion was more like a giant jaguar, or a completely different species altogether than a lion.  The skull does resemble that of a lion, but the lower jaw was more like that of a jaguar.  They theorize that when the glacier cut Beringia and Eurasia off from the North America that the large Panthera cat south of the glacier evolved into two species–Panthera atrox and Panthera onca.  The species of big cats from the Panthera genus in America then consisted of a giant jaguar and a large jaguar.  Panthera onca augusta (the Pleistocene subspecies jaguar)  is considered large compared to modern jaguars, but Panthera atrox was gigantic weighing on average 25% larger than modern African lions.

I think this study makes sense.  If specimens of an extinct cat are consistently that much larger than living representatives of the presumed species, than the chances are good it was a different species.  Moreover, atrox had a larger brain capacity.  This is evidence it may have  hunted in prides like African lions, but we’ll never know for sure.  Based on where most of its skeletel material has been found, it seems to have preferred open country.  The large size of the males would have made it difficult for this species to hunt singly.  At the very least, they must have hunted in pairs.

I’m going to try to get my hands on this paper, so I can give a more detailed discussion in a future blog entry.