Posts Tagged ‘Arctodus simus’

6 Scariest Species to have Ever Lived in Georgia

October 30, 2016

6. The Hell Pigs

Vicious entelodonts lived on earth from the late Eocene to the mid Miocene (for over 20 million years).  They were 4 feet tall and reached weights of 930 pounds.

Entelodonts are known as hell pigs because their fossil remains represent a once terrifying animal that resembled a giant pig.  They occurred across most of the Northern Hemisphere, and there were many species over time.  Entelodonts existed between 37.2 million years BP-16.3 million years BP.  Although they resembled pigs, anatomical evidence suggests they were more closely related to the common ancestor of hippos and whales.  Enteledonts were 4 feet tall and weighed up to 930 pounds.  They were fast runners, and paleontologists believe they rammed into their prey, knocking their victims down and biting them until their bones were broken, probably similar to the way hippos kill humans in Africa today.  Fossil evidence of enteledonts has been found in Twiggs and Houston Counties in Georgia.  The tooth found in Houston County compares favorably with Archaeotherium, a once widespread species of enteledont.

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Entelodont tooth found in Bonaire, Georgia.  I am not the author who took a photo of this tooth. This photo was made by Thomas Thurman and it’s from his http://www.georgiasfossils.com website.

4. (tie) The Giant Short-faced Bear (Arctodus simus) and the Saber-toothed Cat (Smilodon fatalis)

I can’t decide which 1 of these was more frightening.  Giant short-faced bears were on average as large as Kodiak bears–the largest subspecies of brown bear ( Ursus arctos ).  However, they probably made a lot of noise and could be easily detected and avoided.  Saber-tooths were ambush predators and could sneak up on prey in the dark or in thickly vegetated habitat.  Arctodus was much larger, weighing about 1000 pounds compared to ~350 pounds for Smilodon.  But the latter was very powerful and sported fangs.  Fossil evidence of this big cat has been found in all of the states bordering Georgia.  Fossil evidence of Arctodus has turned up in an Alabama county adjacent to Georgia as well as several sites in Florida.  Both undoubtedly once ranged into Georgia.

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Giant short-faced bear and saber-toothed catThe illustration of this saber-tooth is inaccurate.  Smilodon had a bob-tail and their forelimbs were much more powerfully built than depicted here.

3. Appalachiosaurus

 

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Appalachiosaurus terrorized upstate Georgia during the late Cretaceous.

Appalachiosaurus was a species of tyrannosaur that lived on the eastern side of the Western Interior Seaway during the late Cretaceous (~80 million years BP-65 million years BP).  They were the top land predator, probably hunting hadrosaurs or anything else they could catch.  Fossil evidence of this species has been excavated from Hannahatchee Creek near Columbus, Georgia.  The type specimen, a nearly complete skeleton, was found in Alabama.

2. Deinosuchus rugosus

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Evidence suggests Deinosuchus rugosus ate tyrannosaurs.

This extinct crocodylian, a relative of alligator ancestors, grew to an estimated 36 feet long and weighed up to 17,000 pounds.  They were large and powerful enough to seize and drag a tyrannosaur into the water, and there is some fossil evidence they preyed upon them.  They likely ate dinosaurs as a significant part of their diet.  Fossil evidence of this species has also been found in Hannahatchee Creek as well as the Chattahoochee River in Georgia.

1. Man (Homo sapiens)

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Homo sapiens is clearly the scariest species to have ever walked on earth.  Here is a photo of an atomic bomb mushroom cloud.  Humans can wipe out entire cities with nuclear weapons.

Human beings construct weapons of mass destruction capable of turning livable habitat into uninhabitable wasteland.  I can’t think of anything scarier than that.

The Saltville Fossil Site in Virginia

August 1, 2013

A dense forest of white pine, spruce, fir, and oak  grew in the Saltville River Valley 17,000 years ago.  There were also some alder swamps and wet sedge meadows, but unlike in the regions to the south and west of this locality, there were no prairies or open woodlands.  The Saltville River Valley is located in southwestern Virginia and during the last Ice Age, this area was much colder than the region located immediately to the south.  The oceanic Gulf Stream that carries tropically-warmed water north as far as the Canadian coast today, instead only went as far north as the Virginia/North Carolina border during the Ice Age.  This meant dry land temperatures in what is now Virginia were as much as 10-15 degrees Fahrenheight  cooler on average than those about 50 miles  further south.  Consequently, the environment in the middle Atlantic States decisively differed from most of southeastern North America.

Location of the Saltville River Valley.

Saltville, Virginia is located in a beautiful valley.  A large lake, known as Lake Totten, covered much of the valley from ~13,500 BP-~8,500 BP.  Salt mining operations have upset the hydrology here, and today as much as 20% of the valley is underwater. 

The Ice Age began waning about 15,500 years ago.  The Laurentide Glacier slowly receded, and the melting ice increased the flow of water into the Saltville River.  Sediment carried by the increased flow formed a mud dam in the Saltville Valley gap, causing the water to backflow and create Lake Totten.  The outflow was captured by another river.  Many of the species of large mammals that lived in North America then were attracted to the abundant salt springs in the area.  The individuals that happened to die during periods of increased sediment flow were buried by mud and preserved for fossil enthusiasts and scientists to find thousands of years later.

An assortment of fossils found at Saltville.  The animals were buried by mud carried by river surges resulting from melting glacial ice to the north.  Paleontologists have to pump out groundwater from their excavation sites here.  Salt mining operations have caused much of the land to flood.

The Saltville fossil site is the most southerly known location where specimens of woolly mammoth (Mammuthus primigenius) have been excavated.  Specimens of Columbian mammoth (Mammuthus columbi) have been excavated here too, showing the 2 species co-existed in some locations.   The 2 species of mammoth have also been found together at a site in South Dakota.  Columbian mammoths ranged much farther south than woolies, having occupied territory as far south as what today is Florida.  Other megafauna species recovered at Saltville include mastodon, Jefferson’s ground sloth, woodland musk-ox, bison, stag-moose (Cervalces scotti), caribou, white tail deer, horse, and giant short-faced bear (Arctodus simus).   Scientists have yet to publish their findings on the smaller species of animals discovered in the fossil deposits.

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Puncture mark on a mammoth heal bone made by a giant short-faced bear’s canine.

Gnaw marks on an ankle bone, probably made by a dire wolf.

A mammoth heel bone excavated from this site has a puncture mark that matches the canine of a giant short-faced bear.  This species of bruin is thought to have specialized in kleptoscavenging.  (See: https://markgelbart.wordpress.com/2012/12/10/bearzilla-the-biggest-bear-in-history/) The ankle bone of the same animal was gnawed on by a canid, probably a dire wolf.

A study of the bone chemistry of fossil herbivores from this site had an unexpected result.  All the herbivores living in this region then ate C-3 (carbon 3) vegetation–trees, shrubs, and some herbs.  Even species such as mammoths, bison, and horses that predominately subsisted on C-4 vegetation (grass) elsewhere were restricted to a diet of twigs, leaves, bark, and herbs here.  This is considered evidence that prairies were absent from this particular region during this time period.  The authors of this study admit their findings weren’t sufficient evidence to make any conclusions about megafauna extinctions.  Yet, they suggested competition between grazers and browsers for the same resources may have caused megafaunal extinctions.  I disagree with this conjecture.  Instead, I think their findings are strong evidence against climate change as a cause of megafaunal extinctions because the study shows these animals were not picky eaters and could adapt well to changing environmental conditions.

Humans apparently killed, butchered, cooked, and ate a mastodon at Saltville 17,000 years ago.  Archaeologists found cut marks on a mastodon’s bones as well as congealed grease that could only be the result of cooking.  They also found heat-cracked rocks used in the cooking process.  Pre-Clovis artifacts found associated with the mastodon bones include 2 sandstone knives, a chert blade made out of rock transported from some distance away, and flakes (debitage) from tool-making.  The site was occupied 3 times prior to the Clovis era.  The most recent pre-Clovis horizon dates to about 15,000 years ago and includes a midden containing hundreds of shells from giant floater clams.  This species of freshwater mussel grows to 10 inches long and used to be abundant in North American waters before modern day pollution and river damming.

giant floater, Pyganodon grandis

Giant floater clam (Pyganodon grandis).  I’ve never eaten a freshwater mussel, but they smell like delicious oysters.

Saltville is not a new site.  Thomas Jefferson knew about fossils found here.  Scientists have been excavating fossils off and on here for over 200 years.  A team from East Tennessee State completed the most recent excavation this year.  They visited local amateur fossil collectors to examine their specimens, and they are surveying caves in the nearby mountains in the hopes of finding more fossils to help piece together the regional late Pleistocene ecology.  We haven’t heard the last about this site.

References:

France, Christine; et. al.

“Carbon and Nitrogen Isotopic Analysis of Pleistocene Mammals from the Saltville Quarry (Virginia USA): Implications for Trophic Relationships”

Paleogeography, Paleoclimatology, Paleoecology 249 2007

Schubert, Blaine; and Steven Wallace

“Late Pleistocene Giant Short-Faced Bears, Mammoths, and Large Carcass Scavenging in the Saltville Valley of Virginia, USA”

Boreas 38 (3) August 2009

Pleistocene Bears of Southeastern North America

March 10, 2011

Nothing demonstrates wilderness more than a robust population of free roaming bears.  During the Pleistocene before people were around to kill them and destroy their habitat, there must have been tens of thousands of bears living within the boundaries of what today is Georgia.  It’s possible that 5 different species could have been found here in the same time span, though we can be more sure there were at least 3 sharing the same range.  Today, only 1 species of bear resides in Georgia–an estimated 5100 black bears still roam the mountains, the Okefenokee Swamp, the Altamaha and Ocmulgee river bottoms, and Houston County.  Occasional stragglers leave these last strongholds and raid urban dumpsters and suburban bird feeders, but these occurrences are rare.  One study of Georgia bears determined that suitable habitat can support 1 bear for every 3 square kilometers.  That means ideally, Pleistocene Georgia hosted a population of 30,000-40,000 bears.  (*Georgia is about 60,000 square miles. 1.86 square miles =3 square kilimeters.  Moreover, during stadials Georgia’s land mass increased by about 10,000 square miles due to the fall in sea level.)

Here’s a review of every known bear species that lived during the Pleistocene in southeastern North America.

Black bear–Ursus americanus

Photo from google images of a black bear in the Okefenokee Swamp.

Ursus abstruscus is the probable evolutionary ancestor of American and Asian black bears which once consisted of a geographically continuous population.  Glacial ice separated the two populations at the beginning of the Pleistocene, resulting in two different species.  Bjorn Kurten notes that Pleistocene black bears grew as large as modern day grizzlies.  I believe Pleistocene black bears were larger and fiercer than their modern day descendents because they had to survive confrontations with saber-tooths, giant panthers, jaguars, and packs of dire wolves.  Cavers and scientists discovered black bear fossils at Ladds and Kingston Saltpeter Cave in Bartow County, and the Isle of Hope Site in Chatham County.  They’re also commonly found in Florida fossil sites but only a few have been recorded from South Carolina.

Florida spectacled bear–Tremarctos floridanus

Photo of a spectacled bear, Tremarctos ornatus,  from google images.  This is the only living species from the once widespread short-faced bear family.  It is a close relative of the extinct Tremarctos floridanus.  Of course, scientists have no way of knowing whether Tremarctos floridanus was also spectacled, but they call it that anyway.

Now extinct, this was likely the second most common species of bear in southeastern North America during the Pleistocene.  Only 1 specimen has ever been recovered in Georgia (at Ladds), but its fossils have commonly been found in Florida and South Carolina.  It’s thought of as primarily a vegetarian, but a recent study of Pleistocene bears concluded that all were opportunistic omnivores that would eat anything they could obtain.  Tremarctos’s range in the late Wisconsinian Ice Age seems to have been restricted to the southeast.  During warm interglacials it expanded as far north as Kentucky.  It probably just lived in the coastal plain of Georgia and South Carolina as well as Florida during colder climatic stages.

Lesser short-faced bear–Arctodus pristinus

Photo of a fossil jaw bone of Arctodus pristinus from Additions to the Pleistocene Mammal Fossils of South Carolina, North Carolina, and Georgia by Albert Sanders.

Photo of fossil bear teeth from the above mentioned publication.

It’s unclear from the fossil record whether this species co-existed with its larger cousin, the giant short-faced bear, or was simply ancestral to it.  Its fossils have only been recovered from a few eastern sites in Florida, South Carolina, Maryland, and West Virginia.  Teeth attributed to this species overlap in size with those of Arctodus simus.  Florida fossils of this species, including those from Leisey Shell Pit, indicate this animal lived from the early to mid-Pleistocene (~1.8 million-300,000 BP), whereas giant short-faced bear fossils in Florida date to the late Pleistocene (~300,000-~11,000 BP).  However, fossils of the lesser short-faced bear were found in South Carolina sediments thought to date from the Sangamonian Interglacial (~132,000-~118,000 BP) which is also considered late Pleistocene.  These South Carolina specimens haven’t been radiometrically dated, so no one knows exactly how old they are.  Perhaps this species did survive as a relic species in some geographical locations until the megafauna extinction.  Arctodus pristinus is considered more of a general feeder; Tremarctos floridanus a more herbivorous species; Arctodus simus a more carnivorous bear.

Giant short-faced bear–Arctodus simus

Dan Reed’s photo-shopped reconstruction of a giant short-faced bear.   

The giant short-faced bear ranks up there with mammoths, mastodons, ground sloths, and saber-tooths as among one of the most spectacular creatures of this era.  Studies suggest it lived by aggressive scavenging.  It’s extremely acute sense of smell detected blood from a great distance.  Then, the beast would relentlessly trot toward the source of the appetizing odor, and its sheer size would intimidate the partially satiated carnivore that actually made the kill into surrendering the carcass.  Arctodus simus fossils are more common in western fossil sites, but a few have been discovered in the southeast, proving it did occur here, at least sporadically.  An Arctodus simus skeleton rested in the Fern Cave system in Jackson County, Alabama which borders northwestern Georgia, until it was discovered by cavers in 1970.  In addition a number of teeth from this species have recently been discovered in north Florida fossil sites, and some Arctodus simus material was also discovered in Virginia.

Grizzly bear–Ursus arctos

Photo of a grizzly bear and cub from google images.

Welsh cave in Kentucky yields grizzly bear fossils dating to about 12,000 BP.  This is the easternmost known occurrence of this species.  Grizzly bears roam hundreds of miles, so it’s likely if they lived in Kentucky then that they must have entered Tennessee.  But the lack of grizzly bear fossils in other southeastern states suggests they never penentrated the region in significant numbers.  Still, I believe a few irregular stragglers may have wandered into what’s now north Georgia.  It may be that the existence of 3 or 4 other species of bears prevented grizzly bears from colonizing much of the southeast during the Pleistocene, and then man arrived, creating another obstacle blocking their migration into the region.  Grizzly bears are a relatively recent addition to North America’s mammalian fauna, but they did live on the continent prior to the LGM, 30,000 years BP.  They’re the same species as the Eurasian and Alaskan brown bears.

If I could live in the Pleistocene (part 4).

For those unfamiliar with this blog, I occasionally fantasize living during the Pleistocene but with modern conveniences, such as an adobe house with woodstoves, solar heating, electricity, and a time tunnel that connects me to the modern world.

I’ve thought of a simple way to observe bears from my abode.  Connected to my Pleistocene house is a 5 story watchtower designed in the shape of a lighthouse in which I can view the surrounding landscape.  I would take a barbecue grill to the fifth story which has a canopy but an open window stretching for 360 degrees around.  There, I would grill meats.  The aroma should attract bears and other carnivores from miles around.  A bear could potentially climb up the side of a light-housed shaped building, so I would have to have some kind of designed guards that would prevent this. 

I would avoid hunting bears, if possible.  I think modern hunters who kill bears are jerks.  I can understand why the pioneers did it.  They didn’t have grocery stores and had to eat and make use of what they could obtain.  But there is no reason to hunt bears today, unless they prove a danger to tourists.  They don’t reproduce as rapidly as deer, and it’s just not ecologically necessary to hunt them.

Bears were a valuable source of meat and fat for early settlers.  Early accounts reveal an important dish of the Indians.  The Indians frequently diced up venison (which is very lean) and fried it in bear fat.  Bear fat was also the number one source of cooking fat in New Orleans in 1800.  It was gradually replaced by lard as the settlers brought in hogs.

 

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.

Reference:

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.

www.bearcreeksanctuary.com/jaglions.htm