Homo sapiens is a Meat-Eater

December 9, 2018

An Hindu vegetarian didn’t like my blog post, “Native American Cannibalism and Dog-Eating,” (See: https://markgelbart.wordpress.com/2012/10/24/native-american-cannibalism-and-dog-eating/ ).  In the comments section he went on a long rant, explaining how humans are frugivores (fruit-eaters) and how humans aren’t anatomically built to eat meat.  He also has a pro-vegetarian website, promoting the same pseudo-science and misinterpretations of scientific facts that he wrote about in my comments section.  He claims meat-eating has been rare throughout human history, and our evolutionary ancestors ate a plant-based diet.  While it may be true that our very ancient ancestors lived on a diet of leaves and fruit with the occasional bird’s egg or insect, humans have evolved significant differences in dietary requirements and capabilities since then.  Meat is actually much easier for humans to digest than plant foods.  For example humans digest 97% of beef but just 89% of flour and 65% of most vegetables.

The ability of humans to digest large quantities of meat helped them survive the harsh climatic conditions of the Pleistocene when edible plant foods often became an unreliable or scarce resource.  If it wasn’t for man’s ability to eat meat, Homo sapiens would likely have become extinct. The added protein also contributed to brain development, making humans more intelligent.  The human brain is a large fatty organ that requires lots of protein.  The larger brain gave humans a crucial advantage over competing species.

The vegetarian’s response to my blog article made me curious about man’s diet during the Ice Age, so I searched for scientific studies of stable isotopic analysis of ancient human remains.  Scientists can determine the past diet of organisms by analyzing their bone chemistry.  I found 2 studies and was surprised to learn just how dependent upon meat at least some populations of humans were.

Image result for neanderthals hunting rhino

Neanderthals relied heavily upon rhino and mammoth meat.

One study determined Neanderthals (H. neanderthalis) enjoyed a diet that was 80% animal and 20% plant.  The authors of this study looked at Neanderthal specimens from Troisiemo Cave in Belgium.  Apparently, Neanderthals relied heavily upon mammoth and rhino for their diet.  Other carnivores in the region fed more on horse, bison, and caribou.  Some scientists believed H. sapiens displaced Neanderthals because they had more flexibility in their diet.  But a 2nd study debunks this notion.  Scientists analyzed the bones of 3 anatomically modern human skeletons from Buran-Kay III, a rock shelter located in Crimea.  The specimens dated to between 37,000 years BP-33,000 years BP–shortly after the most recent date of Neanderthals.  They found these early humans also had a meat heavy diet, though they “possibly” ate more plant foods than Neanderthals.  This population of humans ate Saiga antelope, red deer, horse, and hare; but mammoth was their most important source of food. This study suggests H. sapiens competed with H. neanderthalis for the same food resources.

Image result for bloody sliced sirloin steak

The vegetarian claimed meat is not appetizing and kept comparing it to “roadkill.”  Meat looks appetizing to me.

Image result for dry rub ribs

I’ll eat this roadkill every time.

Humans have continued to evolve since the Pleistocene.  The agricultural revolution has made plant foods more available, and the human body has evolved to eat more of them.  So, I don’t agree with the paleo-diet fad either.  I believe in eating a balanced diet that includes all 4 food groups.

References:

Drucker, D; et. al.

“Isotopic Analysis Suggests Mammoth and Plants in the Diet of the Oldest Anatomically Modern Humans from far Southeastern Europe”

Scientific Reports 2017

Wilburg, C.; et. al.

“Isotopic Evidence for Dietary Ecology of Late Neanderthals in Northwestern Europe”

Quaternary International 2015

Advertisements

Pleistocene Anhingas

December 3, 2018

I saw an anhinga (Anhinga anhinga) on my trip to Florida last week.  It was on the edge of a pond on the golf course behind my sister’s house.  I always see more wildlife there than I do in Florida’s much vaunted preserves and parks.  Anhingas belong to the Anhingidae family which includes just 1 genus and 4 species, but they have a wide distribution in the tropical to warm temperate regions of North America, South America, Africa, India, and Australia.  The Anhingidae family diverged from the cormorant family (Phalacrocoridae) early during the Miocene about 25 million years ago, and there is fossil evidence of anhingas in Florida during the late Miocene.  This early Florida anhinga goes by the scientific name of Anhinga grandis.  Anhingas probably originated in South America and later spread throughout the world.  There were 2 species of anhinga that co-existed in Florida during the Pleistocene–the extant A. anhinga and the extinct A. beckeri.  Anhinga remains have been recovered from 15 sites in Florida but A. beckeri fossils are known from just 4 sites.  Little is known about this extinct species, but it probably became extinct following the end of the last Ice Age when rising sea levels inundated important rookeries.  Anhingas often nest in colonies with herons and egrets, and the extinct species likely just never moved its breeding range to higher land as other species did.

Image result for Anhinga anhinga range map

Anhinga range map.

Video of an anhinga swimming.

Anhingas are often seen drying their wings after swimming in the water while hunting for fish.  

Anhingas are also known as darters or snakebirds.  Note the snake-like head.

Anhingas hunt fish, amphibians, reptiles, and large invertebrates.  They swim underwater and impale their prey with their long bills.  When they return to shore they toss their prey up in the air and swallow it whole.  Crocodilians prey upon anhingas, but the birds are a dangerous adversary.  They aggressively fight predators with their bills, aiming for the eye.  A scout who guided the first academic ornithological expedition to the Okefenokee Swamp was blind in 1 eye because his pet anhinga had gouged it.  The anhinga is another amazing adaptable animal that has survived for millions of years.

 

Paynes Prairie State Park in Florida

November 26, 2018

My visit to Paynes Prairie State Park was a colossal disappointment.  Paynes Prairie is an area where the Florida aquifer (a gigantic underground river) comes close to the surface.  During periods of heavy rain it fills with water and becomes marshy, but during droughts the water level recedes and parts of it host grassy environments.  The fluctuating water levels prevent trees from becoming established, and it contributes to the open nature of the landscape.  A forest dominated by live oak, slash pine, palm, and red maple with an undergrowth of saw palmetto surrounds the prairie.  Supposedly, bison, cracker cattle, and Spanish horses roam the park; and guides claim it is 1 of the best bird-watching sites in the U.S.  I didn’t see any of the megafauna and only saw a paltry 4 species of birds–an egret, a turkey vulture, a red-shouldered hawk, and a small gray bird with a white tail that I have frustratingly been trying to identify for years.  I’ve seen this bird in Augusta, Georgia too, and it always seems to be hanging around water, but it doesn’t resemble any the pictures in my field guides.  I also heard chickadees and an eastern phoebe.

This egret was the only wading bird I saw in the park.

Fluctuating water levels create an open landscape at Paynes Prairie.  I took this photo from a watchtower that swayed in the wind.

I didn’t see the bison, cracker cattle, or horses.  I did find deer hoof prints.

Some of the live oaks were 6 feet thick in diameter.

I saw more wildlife in Florida outside the park than I did inside it.

Next to my hotel in an urban area of Bradenton, Florida I saw a flock of 13 white ibis.

I got an even better photo of an egret next to my hotel than I did in the park.

The Page-Ladson Site in Northwest Florida

November 19, 2018

I wrote a new blog article about this last night, but then realized I’d already written an article about this subject. I’m re-running this article this week because I don’t have time to write another one before the holidays. Happy Thanksgiving.

GeorgiaBeforePeople

During the late Pleistocene sea level contracted because much of earth’s atmosphere was locked in glacial ice.  The land area of what today is Florida doubled in size, and shorelines extended 50-100 miles west into the Gulf of Mexico.  The water table fell and many present day small rivers did not yet exist.  Instead, the land was pockmarked with many spring-fed ponds that attracted herds of megafauna and other wildlife.  The basal chemistry of these waters preserved bones and organic matter, and later when water tables rose, the Aucilla River began flowing and it covered these ponds with sediment.  The Aucilla River flows over 4 known Pleistocene pond sites–Page-Ladson, Latvis-Simpson, Sloth Hole, and Little River Quarry.  These sites contain deep layers of mastodon dung deposits.  Bones and artifacts are often mixed with the ancient piles of turds, and tracks are also visible where mastodons stepped on their own shit.  Scientists…

View original post 794 more words

Ants, Flies, and Trillium

November 12, 2018

Woodland herbs in the trillium family have evolved interesting traits that lure insects into helping them reproduce.  The trillium family belongs to the lily plant order, and it includes 45 species and 5 hybrids found in North America and Asia.  More species live in North America and the center of trillium evolutionary origin is probably the southern Appalachians.  Species of trillium were likely widespread in the tropical to temperate forests that occurred across both continents during the Miocene over 5 million years ago.   This is likely when trillium evolved a dependent relationship with bees, ants, and flies.  Some species of trillium, such as the great white (Trillium grandiflorum) produce flowers that attract bees and wasps with a sweet smell.  But others, such as the inaptly named little sweet betsy (T. cunacateum), have flowers that smell like rotting meat, and the red color looks like flesh, so they attract flies.  These flying insects help pollinate the trillium plants.

Image result for Fly pollinating little sweet betsy

Little sweet betsy–more accurately known as bloody butcher because they smell like rotting meat. The flesh color and carrion smell of the flowers attract flies, and in turn the flies pollinate the flowers.

Image result for Trillium grandiflorum

By contrast the flowers of the great white trillium smell sweet and attract bees and wasps for pollination help.

Image result for Aphaenogaster picea carrying trillium seeds

Ants disperse trillium seeds throughout the forest.  Aphaenogaster picca is an example of an ant species that mostly preys on termites but takes advantage of the passive trillium seeds when they have a chance.

Trillium produce a fruit with over a dozen fat covered seeds that attract ants.  This layer of fat is known as the elaiosome, and it surrounds a hard seed.  The ants carry the fat rich seeds back to their nest, but discard the hard seeds after consuming the nutritious coating.  This helps spread the species throughout the environment. Most of the species of ants that consume trillium seeds normally prey on termites, worms, and grubs–the trillium seeds are an easier meal that puts up no resistance.  Plants that depend upon ants to disperse their seeds are called myrmecochorous.

For years many scientists were mystified at how trillium and other plant species so rapidly recolonized land formerly covered by glaciers. This is known as Reid’s paradox defined as the unexplained mystery of how some plant species apparently recolonized post glacial habitats faster than their modern dispersal rates suggest.  It is mathematically impossible for ants to have dispersed trillium across New England and parts of Canada in less than 10,000 years. However, scientists recently discovered deer feces containing viable trillium seeds.  Apparently, white tail deer eat trillium fruit and spread the seeds into new territory.  This would answer Reid’s paradox.  However, high populations of white tail deer can be detrimental to trillium populations.  Trillium plants are perennials, capable of surviving from the same root for up to 25 years, but repeated deer consumption of the leaves can kill the plant.  Deer also choose to eat the largest trillium plants, thus selecting for smaller and less productive individual trillium plants.  I hypothesize extinct tapirs and possibly long-nosed peccaries also fed upon and dispersed trillium during the Pleistocene.

The relict trillium (T. reliquum) is known from just 50 sites along the fall line, mostly in Georgia. A genetic study determined this species survived in 2 different Pleistocene refuges during Ice Ages when much of the landscape became desert like.  There is actually greater genetic diversity on the eastern and western parts of its range rather than in the central part.

Image result for trillium reliquum

The relict trillium, also known as the Confederate wake robin.  It is an ancient species that became rare because of Ice Ages.

References:

Gonzalez, E.; and J.L. Hamrick

“Distribution of Genetic Diversity among Disjunct Populations of the Rare Forest Understory T. reliquum”

Heredity 95 2005

Velland, Mark; et. al.

“Dispersal of Trillium Seeds by Deer: Implications for Long Distance Migration of Forrest Herbs”

Ecology 84 (4) 2003

ABC Bears

November 5, 2018

During the Ice Age the coast of southeast Alaska was studded with ice floes and perfect habitat for seals and polar bears.  The interior of Alaska was mostly grassy steppe, the preferred habitat of brown bears.  About 16,700 years ago the icy habitat along the southeast coast of Alaska began to melt and polar bear populations became stranded on Admiralty, Baranet, and Chichagof Islands; also known as the ABC islands.  Here, the habitat began to become more favorable for grizzly bears, and young males looking for new territory not already occupied by adult males colonized the islands.  A genetic study of 1 specimen from this island group determined these colonizing male brown bears mated with female polar bears, creating an hybrid population  (Ursus arctos x U. maritimus).  Gradually, the population of brown bears swamped the DNA of this region, so today polar bear DNA makes up just 6% of their X  chromosome (the female chromosome is XX; the male is normally XY).  Polar bear DNA has also been found in specimens of the extinct Irish brown bear.  DNA evidence suggests polar bears diverged from brown bears about 4 million years ago, but there has been periodic hybridization in regions where the 2 species overlap.

Image result for ABC islands in Alaska

Location of the ABC islands.

Image result for polar bear/brown bear hybrid

Top 2 photos are polar bear/brown bear hybrids in captivity.  Bottom right is a polar bear; bottom left a brown bear.  The 2 species rarely do hybridize in the wild.

A few months ago, Discovery Channel aired a program about the ABC bears that I lambasted in this blog article https://markgelbart.wordpress.com/2018/06/04/the-fear-island-special-that-aired-on-animal-planet-last-night-was-full-of-shit/ .  Previously, Discovery Channel has aired programs about Bigfoot, mermaids, and the extant existence of a 60 foot long extinct species of shark.  I assumed this program was completely bad pseudo-science, but 1 of my readers alerted me to the scientific merits of this program and also informed me that I wrongly assumed the ABC islands were the same as the Kodiak islands.  The Kodiak islands are on the other side of the Gulf of Alaska, so I errored geographically by hundreds of miles.  And the expedition on this program did have scientific merit because they were seeking just the 2nd DNA sample from an ABC bear.  However, I still think this program was full of shit…just not as full of shit as I initially assumed.  Here is why I stand by my first opinion:

1. The participants acted as if they were the first researchers to ever obtain DNA evidence from a bear on the island, though a study of 1 specimen had already been published.  They already had a good idea what they were going to find, and it was not a great mystery as they promoted.

2. The Indian guide claimed he saw 6 bears ceremonially bury another dead bear.  What unscientific bull crap.

3. I don’t buy the size estimate claim.  It was based on an up close trail cam photo.  Weigh it or just shut up.

Reference:

Cahill, J; et. al.

“Genetic Evidence for Island Populations Conversion Resolves Conflicting Theories of Polar Bear Evolution”

PLOS Genetics 2013

 

Terrifying Trench Warfare Caused the Flu Pandemic of 1918

October 29, 2018

Halloween scares are silly compared to the real world.  The universe is a really scary place, considering the potential for random disasters that could wipe out life on earth or at least a large segment of it.  Supernovas, asteroid impacts, tsunamis, and tornadoes are far scarier than a kid wearing a mask.  The other day I saw my cat terrorizing and killing a baby squirrel, and I thought to myself how harsh the universe can be for living organisms.   That particular animal never had a chance.  One would think humans would always be comforting and helpful to each other because the universe is so unforgiving.  History shows just the opposite is often true.  Humans kill other humans–a behavioral trait inherited from their evolutionary ancestors.  During the 20th century this frightening trait was illustrated in 2 world wars that left 67 million people dead.

Image result for WWI no man's land

No man’s land on a battlefield in France during WWI.  Imagine being ordered to cross this into an hail of burning steel.

Image result for trench warfare

Before the widespread strategic use of tanks trench warfare resulted in years of bloody stalemate on the Western front during WWI.

World War II caused more deaths than WWI, but battles in the earlier conflict were bloodier.  Men fought in static lines of trenches before the widespread use of tanks.  During WWII mobile tank warfare led to breakthroughs when many army divisions could be surrounded and thousands of troops would be forced to surrender.  Being in a prisoner of war camp sucked, but it was better than death.  But during WWI generals tried to break through enemy trench lines by bum-rushing opposing trenches with a mass of soldiers.  It was like forcing living human flesh through a meat grinder.  At the sound of a whistle 20 year old men were ordered to run across a devastated landscape known as “no man’s land.”  They ran into machine gun fire, artillery barrages, minefields, barbed wire, and poison gas.  Men were slaughtered and these attacks frequently failed.  Death notices were sent to thousands of families, following these futile offensives.  Just think how terrifying it was for these young men to know they were facing near certain death at the sound of a whistle.

The short lifespan of troops participating in trench warfare selected for an unusual strain of virus.  Most influenza viruses are not that deadly because if the host dies rapidly, fewer virus spores will survive to infect other hosts.  But hosts were dying rapidly in WWI trenches, and a virulent strain of virus, known as the Spanish flu, was just as likely to infect other hosts as the less virulent strains.  The virus began to spread in the spring of 1918.  Demobilization during the fall of 1918 when soldiers rejoined the civilian world caused a surge in the pandemic.  The Spanish flu continued to afflict the populations through the winter of 1919.  Scientists estimate this influenza virus killed 50-100 million people–probably more than both world wars combined.  It infected 25% of the world population and had a mortality rate of 5%-10% (most influenza viruses have a mortality rate of .1%).  Healthy people in their  20’s and 30’s suffered an higher mortality rate than the elderly who are usually more vulnerable to flu epidemics.  Scientists think this flu strain was different from the initial flu strain this generation first encountered during the 1890’s, and their imprinted immune systems were maladapted for it.

Image result for spanish flu virus

Spanish flu virus.

Image result for people dying of Spanish flu

The Spanish flu virus may have killed up to 100 million people.

I’m not afraid of vampires, werewolves, and witches; but the possibility of global war and disease pandemics are much more frightening to contemplate.

Reference:

unnamed author

“A Deadly Touch of Flu”

The Economist September 29, 2018

Peccary Cave in Arkansas

October 21, 2018

Perhaps the best site for Pleistocene fossils in Arkansas is Peccary Cave located in Newton County.  The site was first excavated in 1960s, and a follow-up expedition prospected for fossils again in the early 1990s.  The fossil remains of at least 51 species of mammals have been found here. 4000 specimens of a minimum of 64 individual flat-headed peccaries (Platygonus compressus) were discovered in the cave, hence the name.  The bones of other extinct species excavated from the cave include mammoth, mastodon, bison (Bison antiquus), stag-moose, helmeted musk-ox, tapir, beautiful armadillo, and dire wolf.  There are also remains of extralimital species found here that no longer occur in the region–grizzly bear, pine marten, porcupine, heather vole, and numerous other rodents and insectivores of northern affinities.  Plenty of species still found in the region are represented in the cave as well such as beaver, otter, muskrat, raccoon, coyote, gray fox, opossum, and either mule or white-tailed deer. Reptile and amphibian specimens have been excavated from the cave along with a few human-made artifacts of unknown cultural origin.

Map of Arkansas highlighting Newton County

Newton County, location of Peccary Cave.  

Image result for Platygonus compressus

Illustration of the flat-headed peccary.  Peccaries didn’t use Peccary Cave as a den.  Instead, they either fell inside or their bones were washed into the cave when the nearby creek flooded.  Birds of prey dropped or defecated smaller animals into the cave from overhanging trees.

The fossils represent several different climate phases.  The lowest level contains fossils over 22,000 calendar years BP, a climate phase that includes a weak interstadial and the following early glacial maximum.  Mixed Ice Age woodlands of spruce, pine, and hardwoods interspersed with prairies predominated.  7 different species of squirrels lived in the region then, showing how many diverse habitats occurred here.  Red squirrels and least chipmunks, now absent from the region, preferred spruce forests; gray squirrels, fox squirrels, and southern flying squirrels occur in temperate hardwood forests; woodchucks like meadows; and 13-lined ground squirrels require tree-less plains.  The author of the study discussed below thinks the following glacial maximum caused the entire Missouri Plateau to become inhospitable desert because there are few fossils from the site, dating to between 21,000 calendar years ago-15,000 calendar years BP.  Undoubtedly, the region became more arid during this climate phase, and desert scrub grassland likely predominated, but I think there are alternative explanations for the lack of fossils during this time period here: a) the cave entrance may have become closed and/or b) the barren landscape allowed animals to see the trap entrance and avoid it whereas before it was hidden by thick vegetation and animals frequently fell inside.  Without overhanging limbs there was no perch for birds of prey to drop of defecate the remains of their meals.  Moreover, the nearby creek dried up, so there were no floods to wash fossils into the cave.

The upper level of sediment represents a warm dry interstadial post 15,000 calendar years BP when the region was dominated by grassland.  Bison fossils appear during this phase, and toad fossils outnumber frog bones.  Toads can survive better than frogs in more arid climates.

Kurt Wilson wrote his PHD thesis about the peccary and dire wolf bones found in Peccary Cave.  His paper has interesting information, but it is incompletely researched, and his conclusions are logically flawed.  He believes flat-headed peccaries were always an uncommon species.  Part of his reason for this assertion is based on his incorrect observation that “the southeast is virtually devoid of records (of flat-headed peccaries), except for a dozen localities in Florida.”  Wilson is unaware of 2 sites in north Georgia (Yarbrough Cave and Ladds) and 1 site in coastal South Carolina where fossil remains of flat-headed peccaries have been found.  It is also illogical to assume a species was absent from a region based on its absence in the fossil record.  Large areas of the southeast are devoid of fossils because the local geology is not conducive to fossil preservation, not because animals didn’t live there in the past.

Wilson concludes flat-headed peccaries became extinct due to climate change based on 4 lines of evidence that are easily debunked.

1. He dismisses overhunting by humans as a cause of flat-headed peccary extinction when he regurgitates the tired old claim of Meltzer and Grayson (an archaeologist and anthropologist…not paleoecologists) that there isn’t enough archaeological evidence of human interaction (kill sites) with this species.  I consider this reasoning absurd in the extreme.  99.999…etc% of animals that ever lived on earth left no fossil evidence whatsoever.  It has always seemed unreasonable to me to expect the remains of the final populations of a species that overlapped with man for less than 2000 years to be preserved in the fossil record.  The chances of this happening are tiny.  I’ve noticed Grayson’s recent book published in 2016 is frequently being cited in new papers about Pleistocene vertebrates.  Grayson was blatantly dishonest in this book in the way he characterized a study that rules out climate change models of extinction.  (See: https://markgelbart.wordpress.com/2017/01/23/donald-graysons-disingenous-case-against-overkill/ ) Grayson lied and he knows he lied.

2. Wilson assumes flat-headed peccaries became extinct in this region about 22,000 calendar years BP because their remains don’t occur in cave sediment after this date.  (When Wilson writes of extinction in his paper he means regional disappearance or extirpation because he’s aware terminal dates for this species in other regions are 11,000 calendar years ago.  Nevertheless, he clumsily never makes this distinction in his paper.)  He asserts peccaries became extinct here because the climate became too arid for them.  Again, he is basing his assertion on the dubious assumption that the absence of evidence is evidence of absence.  I think flat-headed peccaries were probably even more abundant during the arid climate phase because they were anatomically well-adapted to dry dusty environments.  Flat-headed peccaries had extensive structures in their nasal passages that helped filter dust.  Wilson must be unaware there are at least 9 fossil sites where herds of flat-headed peccaries were buried during sandstorms.  (See: https://markgelbart.wordpress.com/2013/03/10/when-sand-dunes-buried-herds-of-flat-headed-peccaries/ ) This suggests they were common in desert environments.  Flat-headed peccaries may have avoided falling in Peccary Cave after 22,000 calendar years BP because the area around the entrance to the cave was barren and not hidden by vegetation.  None happened to fall in the cave after this date, but that doesn’t mean they didn’t still occur in the region.  Other fossil sites in the region yield the remains of horses, but not a single horse fossil has been found in Peccary Cave.  Horses were likely another abundant species in the region that just happened to never fall in or enter Peccary Cave.

3. Wilson did a stable isotope analysis of 2 flat-headed peccary teeth and concluded they fed upon just a few leguminous plant species, so they became extinct when these limited number of plant species disappeared from the region.  I don’t believe the entire dietary breadth of a species can be determined from such a small sample size.  Moreover, 1 study suggests stable isotope analysis is not at all reliable.  (See: https://markgelbart.wordpress.com/2016/06/24/trust-the-coprolites-not-the-stable-isotope-analysis/ )  Scientists compared the results of a stable isotope analysis of moa bones with actual fossil droppings.  The stable isotope analysis was wrong.  Flat-headed peccary teeth were built to eat grass and tough vegetation.  A species that survived millions of years of climate change didn’t exclusively feed upon just a few species of leguminous plants.

4. Wilson asserts flat-headed peccaries were uncommon and thus vulnerable to extinction.  However, a new genetic study of 12 flat-headed peccary individuals from Sheridan Cave, Ohio, dating to just before their extinction revealed populations of this species were diverse and expanding.  This suggests flat-headed peccaries were common, adaptable, and had a wide geographical distribution until the species’ demise.

Peccary Cave has yielded a wealth of information for paleoecologists, and I’m shocked at how little research has been published about this site.  I’ve been able to find about half a dozen research papers.  There hasn’t been a scientific excavation of the site since 1993, though amateurs are currently pillaging it.  Most of the specimens from this site have not yet been described in the scientific literature, and they are not listed on the paleobiology database. An early report of the site mentions the existence of peccary “droppings.”  Yet, nobody has studied the coprolites (please email me if I’m wrong)–an outrageous oversight.  We could actually find out what flat-headed peccaries ate, instead of guessing based on stable isotope analysis.  I’m not sure the coprolites were even collected and stored in a museum.  There should be hundreds of published papers about this site, not just a paltry 6.  I’ve come across other understudied fossil sites and collections in my research, but this site might possible be the most underappreciated.

References:

Bell, Kenneth; and Lee Davis

“Sinkhole Excavations in Peccary Cave, Newton County, Arkansas”

Arkansas Academy of Science 47(30) 1993

Davis, Lee

“Biostratigraphy of Peccary Cave, Newton, County, Arkansas”

Arkansas Academy of Science 1969

Perry, Tahlia; et. al.

“Ancient DNA Analysis of the Extinct North American Flat-headed Peccary (Platygonus compressus)”

Molecular Phylogenetics and Evolution 2017

Wilson, Kurt

“Late Pleistocene Extinction of the Flat-headed Peccary on the Ozark Plateau: Paleozoological Insights from Peccary Cave”

Iowa State Graduate Thesis 2017

 

 

 

Pleistocene Pine Voles (Pitymys pinetorum)

October 16, 2018

Evolutionary biologists like to study rodent fossils.  Rodents occur in high population numbers, and their rapid generational turnover means evolutionary change occurs faster than with larger slower breeding animals.  Scientists recently studied pine vole teeth from 2 caves in Kentucky and 1 cave in Georgia that date to the last Ice Age and compared them with modern day pine vole teeth.  Pine vole teeth from Hilltop and Cutoff Caves in Kentucky date to about 30,000 years ago, and the pine vole teeth from Yarbrough Cave in Georgia date to about 23,000 years ago.  Pine voles are still a common species, occurring all across eastern North America.  Despite their name, they prefer living in moist deciduous forests where they tunnel under tree roots and feed on roots, seeds, fruit, fungus, and insects.  Their fossorial existence keeps them safe from owls and hawks, though snakes can enter their burrows.  Pine voles are considered arvicolid rodents because their teeth cusps are in the shape of alternating triangles.  Other common arvicolid rodents include meadow voles, lemmings, muskrats, and cotton rats.

Image result for Pitymys pinetorum

Pine voles weigh just an ounce.  They mostly live underground but occasionally venture to the surface.

Image result for Pitymys pinetorum range

Pine vole range.  Pine vole is a misnomer.  They prefer moist deciduous woods, not pine forests.  Nobody knows why the common name is pine vole.

The pine vole teeth from the Kentucky Caves show the pine voles living then were the same size as modern day pine voles living in the region.  However, pine voles living in north Georgia during the Ice Age were larger than modern day Georgia pine voles and about the same size as northern pine voles.  Scientists believe this was in response to colder temperatures.  Bergmann’s rule states that animals living in colder climates generally grow to a larger size because they are better able to retain body heat.  The authors of this study can’t determine whether this large size was the result of inbreeding with northern populations of larger pine voles that colonized the region or natural selection of the local population.

Reference:

Martin, Robert; and K. O’Bryan

“Size and Shape Variation in the Late Pleistocene Pine Vole (Mammalia: Arvicolidae: Pitymys Pinetorum) First Lower Molars from 3 Caves in Kentucky and Georgia”

Paludicola September 2014

A New Study of the Looper Collection

October 9, 2018

Between 1989-1995 Lonnie and Freida Looper hunted for fossils on 19 different gravel bars along the Mississippi River during droughts when the bars became exposed.  These gravel bars are located between Helena, Arkansas and Greenville, Mississippi.  Thousands of years ago, the bones were quickly buried when glacial meltwater pulses flooded the Mississippi River Valley.  The Mississippi River erodes this Pleistocene-aged sediment and deposits the soil and bones on the gravel bars.  For years the Looper family sold replicas of their specimens, but they donated most of the actual specimens to Delta State University.  I don’t think they still sell the replicas, though the Looper’s website remains on the internet.  The Looper family discovered over 550 specimens including 27 species.  A comprehensive study of their collection wasn’t published until 2017.

 

 

 

 

 

 

The Looper family found this Jefferson’s ground sloth claw on a Mississippi River gravel bar exposed during a drought.

During most of the late Pleistocene the Mississippi River entered the Mississippi River Valley through 3 gaps, but all of these flooded following the collapse of the ice dam that unleashed the waters of Lake Agassiz about 12,900 years ago.  Before this the Mississippi River didn’t meander broadly like it does today.  Instead, it was a series of braided channels clogged with sandbars because the water table was much lower then.  Cold glacial meltwater pulses caused cool microclimates within the valley that favored mixed Ice Age woodlands of pine, spruce, ash, aspen, oak, hickory, willow, tamarack, herbs, and grass.  Frequently flooded bottomlands and abandoned dried-out channels hosted alder thickets with beech, walnut, tulip, willow, and grass.  Spruce and jack pine dominated drier upland sites.  These were the types of habitats that supported the animal life represented in the Looper collection.  Some of the species they found were not known to have occurred within the Mississippi River Valley including paleolama, stag-moose, helmeted musk-ox, giant short-faced bear, and manatee.

Image result for diagram of Pleistocene braided Mississippi river

Map of the Mississippi River Valley in relation to the ice sheet during the Last Glacial Maximum. This map doesn’t represent the land area that occupied the continental shelf then.

Image result for braided river

The Mississippi River resembled this modern day braided river during the Ice Age.

Paleolama mirifica was a species known from the coastal plains of South Carolina and Georgia, and throughout Florida; so the specimen found by the Looper family was a first for the region and evidence for a greater range than was previously known. The manatee was likely an accidental migrant that may have perished because it failed to go south during cool weather.  Manatees can’t survive in water temperatures below 68 degrees F.  The Looper family also collected bones of mammoth, mastodon, bison, white-tailed deer, long-nosed peccary, 2 species of extinct tapir, horse, beaver, giant beaver, Jefferson’s ground sloth, dire wolf, raccoon, black bear, giant tortoise, snapping turtle, soft-shelled turtle, unidentified bird, small-mouth buffalo fish, and flat-headed catfish.  Bones of bison and deer were the most common.

Nina Baghai-Riding, the lead author of this new study, thinks the Mississippi River Valley may have been a migratory corridor for some species.  Cool microclimates along the river may have attracted fauna of northern affinities.  Rivers are also rich in food resources as well because a greater quantity and quality of vegetation can grow in more irrigated environments.  The superior feeding opportunity attracted megafauna as well.

Reference:

Baghai-Riding, Nina; and D. Hunley, C. Beck, and E. Blackwell

“Late Pleistocene Megafauna from Mississippi Alluvium Plain Gravel Bars”

Paludicola December 2017

file:///C:/Users/Owner/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/Baghai-RidingLatePleistocenegravelbarpaper%20(3).pdf