Archive for October, 2012

The Red Bat (Lasiurus borealis)–Another Pleistocene Survivor

October 28, 2012

When I was about 10 years old, I woke up one night and heard something flying around my bedroom.  The creature kept clumsily hitting the walls and from the sound of leathery wings smacking into plaster I knew it was a bat and not a bird.  I walked down the hall to my parents bedroom.

“There’s a bat in my bedroom,” I told my mom.

My mom’s not a girly type of woman who freaks out at the sight of a bug, so her reaction really surprised me.  She later told me she thought I was dreaming, and she did not expect to actually see a bat.  But as soon as she turned on the hall light, a big bat, looking just like a prop from a vampire movie, came flying straight toward us.  My mom slammed her bedroom door in my face, and I ducked under the bat which proceeded to fly down the stairs.  A few minutes later, my mom opened the bedroom door a crack and told me to round up my sisters.  She wanted us to sleep in her room that night because she was afraid the bat might carry rabies.

My mom refused to cook breakfast the next morning.  We went to eat at IHOP instead.  My dad owned a private medical practice at the time, and  one of his patients was in the pest control business, so my dad sent him to our house to look for the bat.  He did examine the living room curtain, but evidentally didn’t see the roosting bat.  That night, we watched a war movie on television, and the explosions from World War II artillery awoke the bat.  The bat crawled down the curtain and started flying around the room.  My dad grabbed his tennis racquet, I opened the front door, and he backhanded the bat out the doorway.

Big brown bat (Eptesicus fuscus).  I believe this is the species that startled my mom into slamming her door in my face.

Based on my memory of its wingspan, I believe the bat that invaded our home on Hogarth Avenue in Niles, Ohio circa 1972 was a big brown bat.  They commonly crawl down chimneys and get inside houses.

There are  9 species of bats that range into Georgia today.  During the Pleistocene there were at least an additional 2 species.  The extinct Pleistocene vampire bat (Desmodus stocki) must have lived in what’s now Georgia then.  And prior to the Last Glacial Maximum, Brazilian free-tailed bats (Tadadira brasiliensis) probably lived here as well, but this species has yet to recolonize its former range, since the climate has warmed following the end of the Ice Age.  Fossils dating to ~40,000 BP of this species have been excavated from Mammoth Cave, Kentucky which is far outside its present day range.  Fossil evidence of bats in Georgia is limited to cave dwelling species–gray myotises (Myotis grisescens), big brown bats, and pipistrelles (Pipistrellus subflavus).  The latter species has a wingspan of only 3 inches–a pipsqueak–and can be confused with a large moth when viewed from a distance.  There are several interesting species of bats that roost in Georgia’s forests, and therefore are not as likely as cave dwelling species to be represented in the fossil record.  Rafinesque’s big-eared bat (Plecotus rafinesquii) roosts in hollow cypress trees, and yellow bats (Lasiurus intermedia) exclusively spend days hidden in Spanish moss.  Perhaps the bat best adapted to the climatic fluctuations of the Pleistocene is the still abundant red bat.

The Red Bat (Lasiurus borealis), still extant, is well adapted to climatic fluctuations and is a real survivor of the Pleistocene when climate fluctuations were drastic compared to those of the most recent 11,000 years. 

Unlike most bats, this species is covered in fur and has short ears.  It’s capable of surviving at lower temperatures than any other species of bat, though it does become inactive below 68 degrees F.  They migrate south during the winter but spread as far north as Canada during the summer. They can also hibernate, if necessary.  They roost in trees, shrubs, and even within leaf litter on the ground.  They become active 90 minutes after sunset when they begin hunting for moths (26% of their diet), flies, mosquitoes, crickets, bugs, beetles, and cicadas.  They use echolocation to catch flying insects on the wing and to pounce on crawling arthropods.  Most species of bats give birth to 1 or 2 young, but red bats have litters as large as 5.  The mother bats leave the baby bats at the roost while foraging.  They will transport them to new roosts, however.  7% of the red bat population carries the rabies virus.  A predator such as a house cat or possum could easily become infected, if they find a red bat in the leaf litter.  Surprisingly though, blue jays are the top predator of red bats, mostly attacking the young.

Red bats have been excavated from fossil sites in Missouri, West Virginia, Virginia, Florida, and even Bermuda.  Apparently, a red bat washed up on a Bermuda beach 400,000 years ago and became fossilized.  Red bats are an ancient species and will probably survive the scourge of white nose syndrome, the disease that is wiping out all cave dwelling bats in eastern North America.  Because red bats are a solitary forest dwelling species, they are less likely to become infected with the communicable disease.  They’ll still be with us when, sadly, most other species of North America’s eastern bats are probably going to become extinct–an ecological disaster.

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Native American Cannibalism and Dog-Eating

October 24, 2012

Last year, I wrote several Halloween inspired essays on topics such as Pleistocene vampire bats, dire wolves and lycanthropy, and the Chernobyl Exclusion Zone. (See https://markgelbart.wordpress.com/2011/10/ ) Monstrous extinct animals abound in the pre-history of southeastern North America, and I can choose from  a lot of potentially terrifying topics for Halloween-themed essay material,  but none of the monsters of the past are scarier than Homo sapiens.  Flesh-eating zombies are popular in fiction today.  But the concept of mindless non-entities eating people is laughable nonsense when compared to the true history of live humans eating other humans.  Maybe this is because we assume people have compassion and empathy for their fellows, and it’s shocking when history proves this is not always the case.

I’ve written an irregular series on this blog fantasizing  about how I would live in Georgia 36,000 years BP, if I could bring some modern conveniences back in time with me.  I picked that time because it’s almost certain there were no people here yet.  As long as I had firearms and a secure dwelling, I wouldn’t be afraid of the animals, but I would be afraid of irrational pre-historic people. I’m sure cannibalism has existed among Homo sapiens for tens of thousands of years ever since before modern man evolved, but most of the evidence is gone.  However, there is plenty of documented evidence of cannibalism among various Native American tribes.  They were caught in the act during European colonization.

Indians roasting arms and legs.  Early Germanic tribes in Europe practiced cannibalism as well.  A recently discovered site in Herxheim, Germany dating to 7,000 BP unveiled evidence of spit-roasted humans.  The bones were cut and the marrow sucked out.

The Skidee Pawnee migrated from the Red River valley to Nebraska circa 1400.  They were part of the Caddoan culture.  The Caddoans believed they had to sacrifice a young woman to the morning star or their corn crop would fail.  Although they would sacrifice one of their own if necessary, they preferred to sacrifice a captured slave.  When the Skidee Pawnee raided a village, they’d kill all of the adults.  They’d carry the small children back with them to serve as food on the return journey, and they’d keep the older children as slaves, some of whom were used for the sacrifice to the morning star.  The slaves were treated well, and these ritual sacrifices were made quick and painless–the victim probably even thought they were about to be honored not killed.  But captives meant to be eaten were severely tortured as the following account by Andre Penicaut illustrates.

All the men and women in the village assemble around the flames where these poor fainting persons are tied.  Each family lights its fire before which they place a pot full of hot water, and, when the sun has arisen, four of the oldest savages, each one with a knife in his hand, make incisions in the arms, thighs, and lower legs of the ones hung up whose blood runs from their bodies to the extremities of their feet where four old men receive it in vessels.

They carry this blood to two other old men whose duty it is to have it cooked in kettles, and when the blood is cooked, they give it to their women and children to eat.  After they have consumed the blood, the two dead men are detached from the frame and placed on a table where they are cut up.  The pieces are distributed to the entire assembly of the village, and each family cooks some of it in its pot.  While the meat is being cooked they begin to dance.  Then they return to their places, take the meat from the pots, and eat it.”

The bible story of Abraham’s near sacrifice of Isaac is a reference to human sacrifice in Western culture.  The Judeo-Christian tradition changed this culture, but the story itself suggests human sacrifice was once widespread in Eurasia as well.  Ancient Semitic tribes shared with the Indians the bizarre belief that the Gods needed to be placated by sacrificing young people.

Before battles the Iroquois always pledged to the Sun God that they would eat their enemies.  The French Jesuit priests witnessed Iroquois eating captives.  The Iroquois tortured and ate the patron saint of Canada, Father Jean de Breboeuf.  They baptized him with boiling water, held fire-heated axes to his skin, cut off his tongue to stop him from praying, scalped him, and removed his still beating heart.  They drank his blood before they chopped him up and distributed his meat to be eaten.

Indian scalping an enemy.  Contrary to apologist historians, Europeans did not introduce scalping to Indians.  However, they did add monetary value to scalps.  Removing and saving the whole head was more common than scalping prior to European colonization.  It simply became more convenient to carry  scalps instead of heads when seeking monetary rewards.

Most of the Chippewa tribes abhorred cannibalism, but they would eat Iroquois in retaliation for Iroquois eating Chippewa captives.

There was a cannibal cult within the Kwakiutl tribes which lived in British Columbia.  Only the Hamatsa, the chief of the cannibal cult, was allowed to eat human flesh.  To become a Hamatsa, a man had to kill another Hamatsa, so the number of cannibal chiefs stayed constant.  Other people, usually his wives, brought him human flesh.  They killed people to eat, but they also ate corpses from those who died of natural causes.  The Hamatsa chief ate both fresh and dried human flesh.  Supposedly, the dried human flesh (jerky) was easier to eat.  Slaves were kept as food.  George Hunt witnessed an Hamatsa feast.  The chief ate a mummified human, then bought a slave in exchange for 100 blankets, and he killed her by biting her throat, and he ate her raw.

The Tonkaway lived on a narrow strip of land in south Texas between the Karankawa and the Comanche.  Besides cannibalism, the Tonkaway are infamous for infanticide.  All female babies were thrown to the dogs to prevent inbreeding.  Apparently, all wives were captured from other tribes.  If a parent had a bad dream, they killed the male babies too.  It’s frightening to contemplate this irrational belief system.  The Comanches especially hated the Tonkaway because the latter would eat captured Comanche braves.  The Comanches were ok with the brutal torture to death of prisoners, but not cannibalism.

The Karankawa inhabited the coastal region of Texas.  Although they were well known for cannibalism, the U.S. government used the Karankawas as allies in its wars against the Comanches and Apaches.

A scientific analysis of human feces found at the Cowboy Welsh site in Colorado proves the Anasazi Indians were cannibals.  The site dates to about 950 AD.  Here, at least 1200 lbs of human flesh were processed and eaten.  A mask made fr0m the skin of a human face was excavated from this site.  Imagine a kid showing up for trick or treat with a face mask made literally out of another person’s face.

Native Americans wouldn’t just kill and eat a family, but they’d eat the family dog too.  The Sious, Cheyenne, Paiute, Nez Pierce, and Hidatsa all ate dog until the early 20th century.  The Kickapoo were famous for their puppy stew.  The Aztecs raised fat little dogs which they castrated so the canines would grow even fatter.

Dog-eating in North America dates to at least 9400 BP.  Human feces containing part of a dog’s skull, dog meat, dog brains, fish, bird, and prickly pear fruit was found in Hinds Cave in south Texas.  Dog is still commonly eaten in parts of Asia.

A paleofecal sample.

9400 year old human coprolite found in Hind’s Cave, Texas that contained part of a dog’s skull.

A Korean dog stew.  Looks delicious.  I would eat it…or at least try it.  I have no qualms about eating dog meat.

Reference:

Feldman, George Franklin

Cannibalism, Headhunting, and Human Sacrifice in North America: A History Forgotten

Alan Hood Company 2008

The Contents of Pleistocene Condor Nests

October 19, 2012

The fossil remains of California condors (Gymnogyps californianus) have been found in at least 13 caves located in Arizona, New Mexico, and Texas.  The bones range in age from ~11,000-~25,000 calender years BP.  Apparently, packrats carried the condor bones, along with leftover bones from the bird’s meals, back to their nests where combined with sticks, they became an actual part of the nest itself.  I discussed how packrat urine acts as a preservative in the blog entry I wrote previous to this one.

California condor nest.  Although they often nest in rocky crevices, they also nest in hollow trees, explaining how they lived in the forested areas of eastern North America during the Pleistocene.  Condors can live to be 60 years old but reproduce slowly.

Most of the condor bones belonged to nestlings or individuals that died just prior to the time they would learn to fly and leave the nest.  Sandblast Cave in Arizona contained 64 specimens from 5 individuals as well as egg shells and feathers.  Stanton Cave, also within the Grand Canyon, produced even more–70 bones from 5 individual California condors, plus 1 bone from a teratorn, an extinct condor with a 12 foot wingspan.

The California condors living in the southwest during the Pleistocene scavenged dead mammoth, bison, horse, camel, and an extinct species of mountain goat (Oreomnos harringtoni).  The bones of all 5 species were associated in the packrat middens with the condor bones.  All 5 species are (or were) grass-eaters.  Some mammoth dung found in Bechan Cave (Bechan is an Indian word that literally means bullshit) was 85% dropseed grass by weight.  The environment in the Grand Canyon during the Ice Age must have consisted largely of grassland.

Skull of Harrington’s mountain goat.  It probably looked similar to a modern day mountain goat.  Condors scavenged goats.

Unlike mastodons which primarily ate twigs, aquatic plants, and fruit; mammoths mainly ate grass.  A dead mammoth or mastodon provided tons of meat for scavengers.

During the Pleistocene the California condor ranged all across North America where its fossils have been unearthed in Florida, New York, and even Cuba.  It’s larger extinct cousin, the teratorn, also lived as far east as Florida.  The extinction of the megafauna led to the extinction of the teratorn, and the extirpation of the California condor everywhere except the Pacific coast.  The population of condors living there survived by learning to scavenge dead whales that washed up on the beach.  The author of the below referenced study mentions that it is an ecological mystery why they didn’t survive on the Atlantic coast by scavenging whale carcasses there.  He also wonders why they didn’t persist on the Great Plains where they could have scavenged from the massive bison herds. I’ll offer my conjecture.

Eastern condors may simply never have learned to scavenge primarily on marine mammals.  Although an occasional individual may have fed upon a dead whale on an Atlantic beach, perchance not enough acquired the habit of cruising the beaches for dead marine mammals. Eastern condors may have even been a separate subspecies.  They were heavier and had wider bills.  I suspect they failed to adapt in the east due to sheer random chance.  The explanation for the condor’s extirpation from the prairie region is more complex.  Perhaps, bison populations became scattered and rare following the extinction of the rest of the megafauna.  Forest may have covered much of the prairie region early during the Holocene.  Indian-set fires probably created much of the prairie land, and bison herds later expanded as a result but not til after the condors were gone.  Still, it’s an enigma why they never recolonized the southwest, though a few were sighted there in the 19th century after European livestock were introduced, augmenting the potential food supply.  Man has re-introduced condors to the Grand Canyon, and a few live there today.

Reference:

Emslie, Steven

“Age and Diet of Fossil California Condors in Grand Canyon, Arizona”

Science, New Series 237 (4816) 1987

See also: https://markgelbart.wordpress.com/2011/07/13/pleistocene-vultures-of-southeastern-north-america/

Pleistocene Pack Rat Middens

October 15, 2012

The Neotoma genus includes 22 species of rodents known as packrats in the west and woodrats in the east.  The eastern woodrat (Neotoma floridana) looks like an overgrown field mouse with a brown back and white belly.  They’re entirely vegetarian, feeding on acorns, nuts, and such common woodland plants as Virginia creeper and greenbrier–foods so abundant in the average woodlot that they don’t have to forage far from the safety of their bulky nests.  Unlike the invasive Norway rat (Rattus norvegicus) and the house mouse (Mus musculus), both of which were accidental stowaways on colonial ships, woodrats cause little damage to agriculture.

Eastern woodrat.  Reportedly, they make good pets and do almost no damage to agriculture.  I’ve never seen one.  For some unknown reason they’re absent from the Augusta, Georgia region but live in most the rest of the state.

In Georgia woodrat bones have been found in just about every Pleistocene fossil site where small mammals accumulated, proving they’ve been common residents of eastern deciduous forests here for millenia.  It’s unfortunate, however, that none of the nests they built during the Pleistocene have been preserved in the east.  All species in the Neotoma genus build very large nests out of sticks upon which they urinate.  The sugar in their urine is sticky, and it acts like cement glue that holds the sticks together.  It’s also a preservative that turns the wood into a substance known as amberat.  Amberat preserves the wood for as long as 50,000 years.  Eastern woodrats build their nests in forests under tree stumps or even in trees.  Rain and moist soil eventually destroy these nests.  But western packrats often build their nests in caves and rock shelters where they remain intact for tens of thousands of years.  These ancient nests provide a treasure chest of data for paleoecologists.

Bushy-tailed  packrat (Neotoma cinerea) nest.  The next is so bulky, large predators probably don’t want to waste the energy trying to tear them apart to get such a small meal.  Rats can escape through a back entrance when fleeing smaller predators.  The sticks are cemented together with sugary rat urine.

Fossil packrat nest in a cave.  The rat urine preserves them for tens of thousands of years as long as they are unexposed to rain.

Scientists have analyzed over 2,000 western packrat nests from caves found from Mexico to British Columbia and from west Texas to east California.  By carbon-dating the wood and identifying the species of tree from which it originated, scientists can determine the forest composition at the time the packrat built the nest.  Moreover, packrats have a curious habit of collecting odd objects, and they often carry fossils, feces, and insect remains back to the nest with them.

Diagram showing changes in forest composition over a 25,000 year period based on evidence from packrat middens.  During the Ice Age some associations of tree species were distributed 700 meters lower in elevation than they are today, and many species compositions have no modern analogue.

The evidence from fossil packrat middens suggests certain associations of woody plants were distributed about 700 meters lower in elevation during the Last Glacial Maximum (~28,000 BP-~15,000 BP) than they are today.  Fir, spruce, and limber pine grew together in vast forests below subalpine meadows which in turn were also lower in elevation than they are today.  Juniper, pinyon pine, and oak grew at elevations between 300 Meters -1700 Meters where highland desert prevails today.  Desert vegetation was nearly absent then and so was ponderosa pine which today comprises the largest zone of forest in the Rocky Mountains.  Evidence from packrat middens suggests this commercially important species didn’t dominate western forests until just 500 years ago.  Much of the composition of Ice Age Rocky Mountain environments have no modern analogue.  The association of plant species everywhere is truly random and transient.

On a humorous sidenote I came across this historical anecdote:  In the 19th century starving miners discovered a packrat midden in a cave.  Some of them mistakenly thought it was a kind of candy they considered manna from heaven.  Packrat middens glisten and have a sweetish resiny odor, explaining the delusion.  A few of them dared to eat it.  Needless to say, they became “nauseated” after eating the 10,000 year old wood cemented together with rat urine.

Some Giant Ground Sloths Dug Long Burrows

October 10, 2012

Many interesting habits of the extinct species of Pleistocene megafauna will remain unknown to science because dead fossil specimens inadequately represent the complete behavior repertoire of once living animals.   For example no scientist would have ever guessed that some species of giant ground sloths dug long underground chambers.  Sure, they had big claws and were anatomically built for digging, but scientists assumed they merely dug for roots and tubers.  The surprising discovery of paleoburrows dug by 2 different species of extinct ground sloth reveals a habit no zoologist would have predicted.

Glossotherium, also known as Harlan’s ground sloth.  It lived in North and South America.  It’s 1 of 2 species that we know for sure dug burrows.  Other species probably did as well.

Scelerodotherium, also known as Darwin’s ground sloth.  It lived in South America and also dug burrows.

Since 1928, scientists have discovered 42 paleoburrows dug by giant ground sloths in the Mar del Plata region of Argentina.  These sites are near the Atlantic coast not far from Buenos Aires and are located on floodplains next to or directly in sea cliffs.  They range in age from Pliocene to late Pleistocene.  The tunnels are from 2-4 feet wide and as much as 70 feet long, and they are multichambered.  Some are filled with collapsed sediment while others are still intact.

Photos of giant ground sloth tunnels dug into sea cliffs located in the Mar del Plata region of Argentina.  Click to enlarge.  The photos are from the below referenced paper.

A geologist discovered the first ground sloth burrow known to science in 1928, but it was a minor footnote ignored by paleontologists for 70 years.  This burrow contained the skeleton of a Scelerodotherium and was filled with volcanic ash.  Scelerodotherium was a 1600 pound ground sloth with a skull resembling that of an anteater.  Vertebrate paleontologists at first rejected the idea that ground sloths dug burrows because they thought the animals were too big to be fossorial creatures.  The largest extant burrowing mammal is the African aardvark which grows to 200 pounds.  However, the authors of the below referenced paper determined that these burrows were dug by ground sloths.  The claw marks on the sides and roofs of the tunnels match those of 2 different species of ground sloths–Scelerodotherium (Darwin’s ground sloth) and Glossotherium (Harlans’s ground sloth).  Scelerodotherium was restricted to South America, but Harlan’s ground sloth lived in South and North America, including what’s now Georgia where its fossil remains were unearthed in Yarbrough cave, Bartow County and a few coastal sites.  Harlan’s ground sloth grew to 2400 pounds and was the larger of the 2 species.  Both species had long claws, well developed triceps muscles shaped for digging, and the ability to balance on 2 limbs–all characteristics that enabled them to dig tunnels.  Paleoburrows of armadilloes and pampatheres (extinct giant armadilloes) have also been discovered in the Mar del Plata region.

Ground sloths probably dug their long underground chambers for 2 reasons.  When not feeding, they could retreat into their burrows to avoid predation.  With their backs protected on 3 sides by dirt walls, they could easily defend themselves from a frontal attack by using their long claws.  More importantly, the tunnels provided the sloths with some protection from the elements.  The edentates–the order including sloths, anteaters, and armadilloes–are primitive mammals with poorly developed thermoregulatory systems.  During extremly cold or hot weather, ground sloths could stay in their underground chambers and remain well insulated.  This adaptation explains how some species of ground sloths survived in cold climates.  Fossils of Jefferson’s ground sloth have been found as far north as Alaska and the Canadian Northwest Territories.  Although there’s no direct evidence Jefferson’s ground sloth dug burrows, I think we can safely assume it did based on its fossil distribution.

If we could travel back in time to visit the Pleistocene, ground sloths might be a rare site, even when they were common.  They likely stayed in their burrows through most of the winter, emerging only during warm days to feed.  During hot months, they probably were nocturnal, feeding in the darkness and returning to their burrows shortly after the sun rose.  Their preference for fossorial living explains why their fossils are so often found in caves.  Caves are ready made burrows that provided protection from the elements.

Many extinct and extant organisms used or even depended upon ground sloth burrows.  The fossil remains of a glyptodont were found in 1 ground sloth burrow.  Glyptodonts were physically incapable of digging their own.  Giant tortoises too probably made use of sloth burrows, possibly explaining how this frost sensitive species survived as far north as Bartow County, Georgia during the Ice Age. (See https://markgelbart.wordpress.com/2011/04/15/the-extinct-pleistocene-giant-tortoise-hesperotestudo-crassicutata-must-have-been-able-to-survive-light-frosts/).

Extant gopher tortoises dig burrows that provide habitat and refuge for dozens of other vertebrate and invertebrate species.  There’s no telling how many animals made use of ground sloth burrows.

Reference:

Vizcaino, Sergis; et. al.

“Pleistocene Burrows in the Mar del Plata area (Argentina) and their Probable Builders”

Acta Palaeontologica Polonica 46 (2) 2001 pp. 280-301

See also https://markgelbart.wordpress.com/2011/03/30/does-a-species-of-giant-ground-sloth-still-exist-in-the-amazon-rain-forest/

And https://markgelbart.wordpress.com/2012/08/19/is-the-9-banded-armadillo-dasypus-novemcinctus-a-dwarf-mutation-of-the-pleistocene-species-dasypus-bellus/

The Mississippi Petrified Forest

October 5, 2012

Natural and manmade erosion of Ice Age loess deposits has unveiled a 36 million year old log jam in Mississippi. All of this fossil wood is known as The Mississippi Petrified Forest.  Although individual specimens of truly fossilized wood have been found in every state, this is the only known petrified forest east of the Mississippi.  This National Landmark is privately owned but accessible to the public for a small fee.

Petrified wood.  Today, second growth forest is growing over The Mississippi Petrified Forest.  A thousand years from now topsoil from composted forest leaf litter could re-cover much of the petrified wood.

 Location of The Mississippi Petrifed Forest.  It was created from a flood and log jam on an ancient now extinct river.

Some scientists consider 36 million years ago to be late Eocene, while others consider it early Oligocene.  Whatever the epoch, an ancient river, now extinct, flowed east of where the modern Mississippi River is now located.  The site of the Mississippi Petrified Forest was just north of the Gulf of Mexico then because worldwide sea levels were so much higher than they are today.  A great flood swept over the riverbanks and carried trees down the river until they got stuck in a log jam.  The trees sank and eventually became buried in mud.  The buried wood turned to stone in a process known as permineralization when silicon dioxide replaced organic tissue.  The Latin word for this is petrify.  The wood turns into many different colors depending on the amount of secondary minerals mixed with the silicon dioxide.  Iron oxides turn the stones red, brown, or yellow.  Aluminum oxide turns the petrified wood white; manganese oxides turn them black.  Chrome and copper oxides turn the petrifed wood green.

The trees in this flood-destroyed forest were massive and ancient.  At the time of their felling some were over 1000 years old, more than 100 feet tall, and from 12-15 feet in diameter.  The species of trees included extinct varieties of sequoias, firs, maples, and families of trees that no longer exist.  The climate during this time period was warmer than that of today and probably frost free.  Redwoods, firs, and maples have evolved to survive in cooler climates since then.

Despite the rarity and scientific value of this site, I couldn’t find any scientific literature about it, making this essay briefer than my usual posts.

The Looper Collection

October 1, 2012

The coldest, driest phases of the most recent Ice Age created an environment of sparsely vegetated grasslands across much of North America.  The sand from dried out river beds, and the rock dust from glacier-scoured boulders blew over the landscape, burying many living plants and dead animals.  Much of this sand and grit was deposited in the Tunica Hills region located in northeast Louisiana, southeast Arkansas, and northwest Mississippi. (See also https://markgelbart.wordpress.com/2011/08/28/the-fossil-rich-region-of-tunica-hills-louisiana/)  Streams along the Mississippi River and the great river itself erode through the loess deposits and reveal many Ice Age fossils.  The Looper family prospects for fossils here, and they have an outstanding collection that they have posted online.  http://www.cwreplicas.com/index1.html

Their collection includes over 500 specimens of mammoth, mastodon, Jefferson’s ground sloth, bison, woodland musk-ox, llama, stag-moose, white-tail deer, long-nosed peccary, horse, tapir, giant beaver, beaver, giant short-faced bear, black bear, dire wolf, raccoon, manatee, giant tortoise, unidentified bird, flathead catfish, and small mouth buffalo.  The family also finds and collects Civil War artillery and cannon shells; Indian artifacts such as arrowheads, pottery, and atlatl weights; and Eocene Age marine fossils–sea shells, shark’s teeth, and whale bones.  Lonnie Looper makes and sells replicas of fossils and artillery shells.  I think I may order his replica of a stag-moose tooth which is a particularly rare fossil find in the southeast.

Before the Looper family found the 3 specimens in the below photograph, the stag-moose (Cervalces scotti) was only known from 1 other fossil site in the southeast–the Ashley River near Charleston, South Carolina, and that was just 1 tooth.                     Antler and Jaw Fragments      

Artist’s rendition of an extinct stag-moose

The stag-moose is an extinct species of deer that was formerly more common in wetlands just south of the ice sheet in what’s now Ohio, New York, and Pennsylvania; but apparently a few wandered as far as the mid-south.  Although the common name is stag-moose or elk-moose, it was not closely related to the modern moose.  It was slightly larger than a modern day moose, but its head was more similar to that of an elk, and it had an antler structure unlike any extant species of deer. It was probably a solitary animal and on occasion in the vast unimpeded wilderness of the Pleistocene a few ranged down south from their more usual stomping grounds in the midwest.

The other really unusual and rare fossil from the Looper collection is the radius-ulna of a manatee in the below photograph.

Radius-ulna

If my anatomy is correct, I believe this is the front flipper.  Today, manatees are not found in the Mississippi River, though they occur in brackish lagoons on the west and east coast of the Gulf of Mexico.  This fossil is evidence that during warm interglacials and interstadials manatees ranged farther north than they do today because they can not survive subfreezing temperatures.  One radio-collared manatee did swim as far north as Rhode Island but then returned to Florida before the onset of cold weather.  Various 18th century accounts report mass manatee strandings on the coast of Britain, so they are known for going far off course.  A fossil of a manatee was also found near a creek that feeds into the Ohio River, but the radio-carbon date was just 2,000 BP.  Either the bone was carried by an Indian, or there was a population of manatees in the Ohio and Mississippi Rivers that recently.  Dr. Daryl Domning, a scientist from Howard University, speculates the Little Ice Age that lasted from 1300-1850 may have doomed the manatees from this river drainage system.

During the Pleistocene and possibly the Holocene manatees lived in the Mississippi River.

Dr. Domning noticed that fossils of early Pleistocene manatees (Trichechus manatus) dating to about 1 million years BP are more similar to the subspecies of modern manatees (T. m latirostris) than those of the late Pleistocene manatees (T.m. bakerorum) found in Florida sites.  He theorizes that colder climate caused the complete extinction of T.m. bakerorum.  After the climate became warmer T. m. manatus recolonized Florida from the Carribean, explaining the close similarity between T.m. manatus and T.m. latirostris.

Scientists believe manatees colonized Africa millions of years ago by traveling in a “lens” of freshwater expelled from the Amazon River.  Evidentally, they can spread across wide bodies of saltwater and survive in regions as long as temperatures stay above freezing.

References:

Domning, Daryl

“Fossil Sirenia of the West Atlantic and Caribbean Region VII. Pleistocene Trichechus mantus Linneaeus, 1758”

Journal of Vertebrate Paleontology 25 (3) September 2005

Williams, Michael; and Daryl Domning

“Pleistocene or Post-Pleistocene Manatees in the Mississippi and Ohio River Valleys”

Marine Mammal Science 20 (1) January 2004