Posts Tagged ‘rare earth elements’

An Update on Vero Beach Man

February 5, 2015

I wrote about the Vero Beach mammoth engraving in February of 2012 (See: https://markgelbart.wordpress.com/2012/02/19/the-vero-beach-mammoth-engraving/).  A fossil collector found the bone of an unidentified species of megafauna engraved with the likeness of a mammoth.  This rare artifact was discovered at the Vero Beach fossil site in Florida.  This site was first excavated about 100 years ago.  Human remains were found in the same strata as the remains of extinct Pleistocene megafauna including sabertooth, mastodon, llama, tapir, etc.  The leading archaeologist of the day insisted humans didn’t colonize North America until after the Pleistocene megafauna became extinct.  He believed Indians buried dead members of their tribe, thus explaining why these particular human remains appeared to be in the same strata as the extinct mammals. Years later, overwhelming evidence showed that humans did overlap in time with North America’s extinct megafauna.  However, I had read that no scientist had been able to test the Vero Beach remains because they had been lost.  Either the Vero Beach remains were rediscovered or they were never lost because I came across a recent study in the Journal of Vertebrate Paleontology that did involve testing these specimens.

Paleoindians hunting.  An analysis of rare earth element concentrations confirms human fossils found at the Vero Beach Site were the same age as the megafauna fossils, solving a century old controversy.

The scientists who published this study (referenced below) analyzed the concentrations of rare earth elements to determine humans lived at Vero Beach at the same time as the extinct Pleistocene megafauna.  (Vero Beach was far inland then and not actually a beach.)  The concentration of rare earth elements in ground water varies over time.  Organisms drink this water and the amount of rare earth elements in their bone matches that of the environment at the time they lived.  The human remains had rare earth element concentrations in the same ratio as the Pleistocene mammals.  These levels are higher than are found in modern Floridian mammals.  This evidence resolves a century old scientific dispute, though few modern scientists doubted the Indian remains dated to the Pleistocene.

Reference:

Macfadden, Bruce; and Barbara Purdy, F. Church, and Thomas Stafford

“Humans were contemporaneous with Late Pleistocene Mammals in Florida: Evidence from Rare Earth Elemental Analysis”

Journal of Vertebrate Paleontology 32 (3) May 2012

The Vero Beach Mammoth Engraving

February 19, 2012

About 5 years ago James Kennedy, an amateur fossil collector, found a nondescript scrap of bone near Vero Beach, Florida.  It seemed so ordinary he went home and promptly stuck it in a box under his sink.  But a few months later he took it out of the box, cleaned it,  and discovered it was not nondescript at all–there was an engraving of a mammoth on it.  Paleolithic art on portable objects such as bone, antler, and rock are common in Europe but before this discovery unknown in North America.

Up close view of the mammoth engraving.  The domed forehead indicates it depicts a mammoth, not a mastodon.  The fossil is mineralized and has no DNA left for species identification. The whole scrap of bone is just 16 inches long.  The engraving itself is about 4 inches wide. 

This fossil is an incredible and rare find from a site that has produced a bounty of other wonderful fossils and artifacts, including human remains probably dating to about 14,000 calender years BP.  Of course the first thought to cross the minds of scientists when they initially saw the specimen was the possibility that it might be fake.  But there are several ingenius scientific techniques that can detect whether the artifact is a fraud or not.  By analyzing the ratio of rare earth elements found in the specimen (a method I’ve discussed on a couple of previous blog entries including https://markgelbart.wordpress.com/2011/08/28/the-fossil-rich-region-of-tunica-hills-louisiana/) they determined the fossil dates to the Pleistocene and did come from the Vero Beach site.  After examination of the specimen under a microscope, scientists concluded the engraving showed the same amount of weathering as the rest of the bone.  A fresh engraving would look much clearer than the rest of the bone.  Scientists made a fresh incision on this bone, then used a scanning electron microscope to compare the fresh cuts with the older engraved cuts.  The fresh cuts had a “debris field” (microscopic dust) whereas the engraved one didn’t, suggesting an older debris field eroded away.  Also, it looks as if the mineralization of the bone occurred across the engraving.  Scientists conducted 2 additional tests to determine if the engraving was authentic.  Energy dispersion x-ray spectroscopy can detect whether the specimen was cut, then applied with a substance that made it look mineralized.  No substance they could detect was used.  Finally, they made a cast and mold of the fossil and subjected it to reflection transformation imagery (http://vcg.isti.cnr.it/Publications/2006/DCCS06/).  This helped them determine the engraving wasn’t made recently.

James Kennedy with what looks like a bunch of fossils.

I’m convinced it’s authentic.  From examining Mr. Kennedy’s dwelling (his home?) in the above photograph, he appears to be a working class kind of guy and unlikely to be harboring a method that can fool modern forensic scientific techniques.

According to a Mammoth Trumpet article, the Vero Beach mammoth engraving is being auctioned.  If a museum doesn’t place the highest bid, this specimen could be lost to science.

The whole scrap of bone with the engraving on it.  Geometric designs extended past the broken end. The size of the bone narrows it down to either mammoth, mastodon, or giant sloth.  Not enough is left for scientists to determine which it was.  But without a doubt the engraving depicts a mammoth.  Mammoths had  domed forehead, mastodons didn’t.  If I had to make a bet, I’d gamble the bone is from a mammoth because it’s likely the paleo-indian who engraved it was drawing the animal it was from.

Vero Man was NOT a 12 Foot Tall Giant

While researching the topic of this blog entry, I came across a creationist blogger who claimed the scientists who originally examined the fossils from the Vero Beach excavation found bones of 12 foot tall men.  Supposedly, this supported the existence of giants as recorded in biblical accounts.  I knew this was bullshit, but the creationist had a source–a newspaper article written in 1930.  I assumed the newspaper reporter was probably a sensationalist idiot, incapable of distinguishing his ass from a hole in the ground. I was certain the reporter had never even read the original scientific paper and had gotten his facts confused.  I’ve read hundreds of scientific papers on paleontological discoveries, and scientists always give exact measurements of every single body part when they find something new and different.  So I searched and found the article written by E.H. Sellards in 1916, and much to my delight, it was available for free online.

It’s an excellent paper, quite advanced for its time–realize that in 1915 when workers were digging  the drainage canal that led to the abundant  fossil discoveries here, north Florida was a wilderness with a few subsistence farmers, cotton plantations, and lumber operations.  The canal construction bisected an extinct river bed that formerly flowed into the Indian River lagoon.  The extinct river was about 100 yards across but was shallow.  I suspect it was a kind of brackish stream.  Workers kept finding cartloads of Pleistocene-age fossils, attracting the attention of E. H. Sellards, a geologist, and O. Hays, a vertebrate zoologist.  Dr. Sellards told the workers to look for human remains, though he didn’t expect them to find any because at the time conventional wisdom assumed that Pleistocene mammal extinctions in North America occurred before man’s arrival on the continent.  Much to his surprise, workers and fossil collectors did find human remains in 3 different places along the canal, and human artifacts in 2 additional spots–all associated in the same strata with bones of Pleistocene-age mammals.  This was the first evidence ever that humans co-existed with extinct Pleistocene mammals in North America.  In total they found the remains of at least 5 individual people.

The human specimens from the first locality included leg, heel, feet, and finger bones.  They were found associated with fossils of mammoths, mastodons, horses, deer, and Jefferson’s ground sloth.  The mammal fossils had the same degree of mineralization as the human fossils.

The human specimens from the second locality consisted of ankle, pubic, and finger bones and were found with 7 flint tools.  I’m no expert on lithics, but from the pictures in Dr. Sellards’ paper, they look like scrapers used to scrape fur from hides.  These specimens and artifacts were found associated with fossils of mammoth, horse, tapir, possum, rabbit, cotton rat, armadillo, shrew, alligator, snakes, and acorns.  Lots of good plant fossils were initially discovered, but after exposure to air overnight, all but the acorns, turned to dust.  Dr. Sellards could have used the benefit of modern techniques to prevent this.

The human specimens from the third locality included arm, shoulder, jaw, foot, tooth, toe, and skull bones along with broken pottery, bone implements, and flint arrowheads.

Dr. Sellards also found mammoth and bird bones with human-made engravings.  These were found associated with fossils of horse, saber-tooth, deer, tapir, horse, rabbit, round-tailed muskrat, raccoon, alligator, snake, fish, amphibian, bird, acorns, and wood.

Dr. Sellards wrote “Undisturbed strata over human bones precluded the possiblity of human grave burial intruding into the sediment.”  He even found a heavy rock over some of the human bones.  Moreover, if these were more recent purposeful graves, more of the skeletons would have been found rather than just disarticulated pieces.  Despite Dr. Sellards’ sound reasoning, Ales Hrudlicka, the leading American anthropologist then, insisted these bones were from later Indian burials intruding into the older fossil deposit.  This controversy occurred before the invention of carbon dating which would have settled the issue.  Dr. Hrudlicka refused to believe Indians co-existed with now extinct Pleistocene mammals, even after discovery of Clovis arrowheads in mammoth bones in 1932.  Comically, he once gave a lecture denying this possibility, immediately following presentation of the famous Clovis evidence at a symposium. Some people are just so close-minded, they can’t accept evidence, even after it slaps them upside the head.  Which brings me back to the creationist.

In Dr. Sellards paper he only gives measurements for 1 of the human specimens.  He measured “the lower margin of the lesser tuberosity to the upper margin of the inner condylur on the femur.”  It was 29 cm.  On an average modern human that part of the leg is 32 cm.  So if anything, that particular Indian was smaller than average–not a 12 foot giant as the full-of-shit journalist reported in his article in 1930.  The creationist blogger should have taken the effort to do some critical thinking and deeper research before he regurgitated phony bullshit.

For a century now this drainage canal in Vero Beach has been a productive site for amateur fossil collectors.  In addition to species mentioned above, they’ve found fossils of dire wolves, jaguars, bobcats, llamas, bison, pampatheres (a 300 pound armadillo), and Eremotherium–a really giant ground sloth.  But this will soon be coming to an end.  The city of Vero Beach is planning to cover the canal in concrete and turn it into a sewage outlet, though they are giving scientists extra time to do some last minute collecting before they close this door to the past.

Incidentally, all the human remains from the Vero Beach fossil site were lost.  After their discovery the specimens were shuttled back and forth between the Smithsonian Insitution and Florida State, but by 1947 interested parties lost all track of them.  What a shame.

References:

Lepper, Bradley

“Mammoth Engraved on Bone from Florida”

Mammoth Trumpet (27) 1 January 2012

Sellards, E.H.

“Human Remains and Associated Fauna from the Pleistocene of Florida”

Florida State Geological Survey 1916

The Terror Bird (Titanis walleri)

November 16, 2011

28 million years ago, South America was an island continent much like Australia.  Marsupial lions stalked the land as a top predator, but big birds evolved that rivaled and probably surpassed them in ferocity.  The phorashacids grew to over 6 feet tall and weighed over 300 pounds.  They sported large hatchet like bills and long claws which they respectively used to bludgeon and tear apart small to medium-sized mammals, reptiles, and other birds.  5 million years ago, the continents of North and South America drifted close together, but even before the landbridge joined them, a species of phorashacid, known as Titanis walleri, island-hopped north and colonized the southern half of the continent.

Two different illustrations of the terror bird.  The top picture is from google images.  The bottom is from the June 1997 issue of Discover magazine by Steven Kirk.  Note the stiff T-rex-like arms.  Scientists aren’t sure, if their arms were actually like this, because no fossil arm bones have ever been found.  They assume this based on shoulder bone.  Terror birds were a kind of evolutionary throwback to their velociraptor ancestors, but they differed in some notable ways.  They had no teeth and they didn’t have a long tail.

Terror birds likely found abundant food in North America such as small pronghorns, juvenile horses, deer fawns, rabbits, rodents, reptiles, as well as some carrion and plant foods.  They stalked their prey, perhaps blending in color with thickets where they hid and waited for unsuspecting animals to wander.  Then, with a burst of speed (maybe up to 40 mph) they’d run at the victim and stike them on the back with their hatchet-like bill, paralyzing the prey.   Using dinosaur-like arms, they held the struggling prey down and tore chunks of flesh from the suffering animal.  They probably picked up and dashed smaller prey on the ground before swallowing them whole, not unlike a method used by their closest living relative–the seriamas.

Not a bill from Sesame Street’s friendly big bird.  This is a fossil replica of a terror bird skull.  According to wikipedia, a complete skull has never been found.

Scientists were surprised to find Titanis walleri fossils in Florida.  For birds Titanis has an unusual bone structure.  Most bird bones are hollow, making them light and conducive to flight.  But terror birds couldn’t fly.  Its bones were thick and heavy, like a large mammal’s.  Many of the first bones discovered were labled as horse bones, stuck in drawers in museum basements, and forgotten.  At first scientists in Florida didn’t realized they’d excavated locally what was formerly thought to be a family of birds restricted to South America.  Pierce Brodnorb formally named Titanis walleri a new species in 1963.  Most terror bird fossils were excavated from the Santa Fe River in Florida, but one specimen was discovered in Texas.  (The first to find fossil material of the bird in Florida was Benjamin Waller, a scuba diver.)  In both fossil localities Pleistocene-age fossils are mixed with Pliocene-aged fossils because rivers are eroding through two different aged deposits.  So for awhile, scientists were uncertain how recently the terror bird lived.  Eventually, scientists discerned different chemical signatures from the fossil bones, using an analysis of the ratios of rare earth elements which change over time. (See my blog entry–“The Fossil Rich Region of Tunica Hills, Louisiana,” for a more detailed explanation of how rare earth elements are used to bracket the age of fossils. https://markgelbart.wordpress.com/2011/08/28/the-fossil-rich-region-of-tunica-hills-louisiana/)  None of the terror bird fossils were younger than 2 million years, suggesting it became extinct early in the Pleistocene.

I wonder why such an awesome predator became extinct.  I doubt colder climate was the cause of extinction–there were mini-Ice Ages during the Pliocene.  Giant tortoises survived the harsher Pleistocene Ice Ages, and if they survived these, the terror bird should have been able to as well.  The floral composition of the environment probably didn’t change significantly between the late Pliocene and early Pleistocene.  I suspect it was a new cavalcade of fauna that doomed the terror birds.  Black bears (Ursus americanus) crossed the Bering landbridge about this time.  Pleistocene black bears grew as big as grizzlies and were probably more ferocious than today’s bruins.  Maybe they were able to drive terror birds off their nests.  Maybe wolves and big cats evolved to become more adept at hunting the chicks.   And maybe prey such as rabbits and small ungulates evolved to run in circles and avoid capture.  Terror birds could run fast in straight lines but are thought not to have been efficient at changing directions while pursuing prey.

This is the terror bird’s closest living relative.  A red-legged seriama is bashing a snake against a rock.  They’re an inhabitant of South American grasslands.  They’re much smaller than the phorashacids, growing to only 31 inches long.

A nature documentary  showing terror bird hunting behavior can never be made.  However, their closest living relatives, seriamas (Cariama cristata and Chunga burmeisteri), still inhabit the grasslands of South America where they prey on insects, snakes, lizards, small mammals, and other birds.  They kill their prey by slamming them against rocks as depicted in the photo above and the link to the youtube video below.

http://www.youtube.com/watch?v=u_KT85YbS3w&feature=player_detailpage

The Flock is a pretty good sci-fi thriller about terror birds.  The book may be made into a movie.  The cover of my copy of the book has an alternative illustration.

The Fossil Rich Region of Tunica Hills, Louisiana

August 28, 2011

The Tunica Hills region is located in the geographical corner between southwestern Mississippi and southeastern Louisiana.  Ice Age climate variations instead of tectonic processes created these uplands.  During times of glacial expansion the Laurentide glacier scraped bedrock in the upper midwest, grinding it down into what geologists actually call “rock flour.”  During interstadials meltwater pulses carried this rock flour down the Mississippi River.  The warm climatic phases that caused meltwater pulses always preceded changes to cold arid conditions.  The decrease in precipitation led to a greatly reduced flow in the Mississippi River, and massive amounts of river sediment became exposed to the air in giant sandbars and dunes.  The windy environment of this glacial stage blew this river sediment, which consisted largely of rock flour (also known as loess), to the east where it settled in big hills.  So the Tunica Hills are actually great big piles of midwestern rock dust.  Later, streams (known as bayous in Louisiana) eroded through the hills and cut through fossil deposits of different ages, washing Miocene, Pliocene, and Pleistocene fossils into the water for today’s fossil hunters to find.

Ravine in the Tunica Hills.  The walls are made of midwestern rock dust blown here during the Ice Age.  From google images.

The loess buried and preserved lots of paleobotanical evidence from the last Ice Age–not only pollen but macrofossils such as logs, cones, and leaves.  The age of the pollen and fossil plants gives us a continuous record from 24,500 BP-17,700 BP, the height of the Last Glacial Maximum.  (The Laurentide Glacier reached its southernmost extent 18,000 BP, but I consider the whole time span of ~28,000 BP-~15,000 BP to be the LGM because that’s when Wisconsinian Ice Age climate was the coldest.  However, there were several weak and brief interstadials within this timespan.)  Scientists found evidence of a forest dominated by spruce but with hardwoods such as oak, beech, elm, hickory, walnut, and maple present.  Spruce made up 40%-70% of the pollen, pine 6%-17%, oak 3%-10%, and other hardwoods <2%.  Grass and composites such as aster, daisies, and sunflowers were also well represented, indicating widespread meadows.  Dwarf mistletoe, an interesting parasite that grows on spruce trees, was abundant.

At first scientists misinterpeted this data because they catalogued the spruce fossils as belonging to an extant boreal species–white spruce.  But in 1999 scientists identified the species they were finding as an extinct temperate species they’ve named Critchfield’s spruce.  Formerly, scientist believed that during the LGM the Tunica Hills region was comparable in climate to the modern day Great Lakes region.  Critchfield’s spruce was likely adapted to warmer climatic conditions than white spruce, nullifying this previous assumption.  Instead, climate in Louisiana then was probably only slightly cooler than today.

Conifers and grasses grew better in an Ice Age atmosphere with lower CO2 levels than did broad-leaved trees.   This probably accounts for why Critchfield’s spruce became a dominant tree over hardwoods.   It was lower atmospheric CO2 rather than lower temperatures that facilitated the growth of this forest.   This unique ecotone of dominant spruce with mixed hardwoods and meadows stretched all the way from Tunica Hills east to Kentucky, Tennessee, and western Georgia.  Critchfield’s spruce fossils have also been found in 2 different localites in western Georgia and 1 in Tennessee.  Eastern Georgia and South Carolina had a somewhat different landscape with more pine and oak, though spruce was present.  West of Tunica Hills an open oak (probably bur oak) and cedar savannah prevailed–grasses and composites made up 20%-50% of the pollen, oaks 10%-25%, and spruce 1%-15%.

Today, Tunica Hills supports an unusual forest for the region.  Beech, magnolia, and holly are dominant but many species occur including laurel oak, water oak, osage orange, hackberry, maple, silver bell, paw paw, and river cane.  Cool ravines provide relief from the hot southern sun, so trees with northern affinities grow next to warm climate trees.  A disjunct population of eastern chipmunks resides here.

The Miocene deposit is located geologically in the Pascagoula Formation.  It’s believed to have been an estuary then.  The Miocene (25 million BP-5 million BP) could be known as either the age of the horse or the age of the rhino because they were the 2 most common large mammal species then.

Hipparion–a 3 toed gazelle horse common during the Miocene.  Miocene Louisiana was mostly tropical.

Naturalists excavated specimens of both the hippo-like rhino (Teleoceras) and the hornless rhino (Aphelops) from Tunica Hills.  At least 5 different species of horses galloped the region then–Astrohippus, Cormohipparion, Hipparion, Neohipparion, and Nannihippus aztecus.  They were all 3-toed gazelle-horses.  The cavalcade of Miocene ungulates also included peccaries, tapirs, an extinct species of pronghorn antelope, and the odd synthetocorus

A synthetocorus. What an odd hooved animal.  Note the bone on its nose.

Mammut mathewii roamed what was to become Louisiana then.  It was an early form of mastodon.  Giant tortoise, alligator, snake, and fish remains were collected as well.

Some of these species survived to early in the Pliocene but among the 3-toed horses, only Nannihippus aztecus survived to the end of the Pliocene, sharing the range with the 1 toed modern genera of horses which then included the American zebra.

A list of Pleistocene fossils collected from the Tunica Hills region consists of the familiar animals discussed on this blog–Jefferson’s ground sloth, Harlan’s ground sloth, horse, saber-tooth, giant armadilloes, and grouse.  A glyptodont fossil is the most recent addition to the Tunica Hills fossil list.  This year scientists identified glyptodont scutes and a partial rib from a Tunica Hills creek.  This is the first find of this species between Florida and Texas.

Reconstructed glyptodont displayed at the University of Florida museum.  I don’t know if this is a replica or the real bones.

Scientists refer to fossils found in the bayou as “float” though they don’t literally float but are usually recovered by sifting the bottom.  The age of the fossils in Tunica Hills can’t be determined based on stratigraphy because streams eroded them from different age strata, but scientist have figured out how to used an interesting method to distinguish whether a fossil is late Miocene/early Pliocene or Pleistocene.

Some of the highlighted elements (known as rare earth elements) are the ones that can be used to determine which age a fossil belongs to.  The ratio of these elements varies in the environment over time.

Scientists use knowledge of rare earth elements to determine the relative age of different fossils.  One collegel student, Lindsey Yann, conducted a study for her Masters thesis comparing the ratios of rare earth elements in different fossils found in the Tunica Hills bayous.  Rare earth elements (a bit of a misnomer because they’re not particularly rare) include elements on the periodic table numbered 57-71.  They occur in groundwater in certain fixed ratios.  Animals absorb ground water by ingestion and then for thousands of years after they die their bones continue to become saturated with it.  Eventually, the bone reaches a saturation poiunt and won’t take in any more.  The ratio of rare earth elements in that particular fossil becomes fixed.  However, over millions of years the ratios of rare earth elements in ground water changes.  So an animal that lived 5 million years ago will have a different ratio of rare earth elements than an animal that lived 25,000 years ago.

References:

Jackson, Stephen; and Charles Givens

“Late Wisconsinian Vegetation and Environment of the Tunica Hills Region, Louisiana and Mississippi”

Quaternary Research 41 1994 pp. 306-325

Schiebout, J.; et. al.

“Miocene Vertebrate Fossils Recovered from the Pascagoula Formation in southeastern Louisiana”

Geology Paper

Schiebout, J.

“Fossil Evidence of Glyptotherium C.F. floridanus in the Pleistocene of Lousiana”

GSA paper March 2011

Yann, Lindsey

“Rare Earth Elements as an Investigative Tool into the source, age, and ecology of Late Miocene to Late Pleistocene Fossils from the Tunica Hills, Louisiana”

Masters thesis for LSU

http://etd.lsu.edu/docs/available/etd-06292010-133339/unrestricted/YannThesis.pdf

Parallel Unconformities in Florida and South Carolina Fossil Sites

August 9, 2010

Unconformities often puzzle geologists.  An unconformity is a geological term in the study of stratigraphy for a region where sediment from one age overlays sediment from an older age, but fill from the age in between is missing.  For example at the Peace River fossil site located in southwest Florida, late Pleistocene-age fossils are found in sediment over fossiliferous Miocene-age sediment, but rocks and fossils from the Pliocene and early Pleistocene are completely absent.  Geologists are some times at a loss to explain exactly why unconformities occur in certain areas, and of course, creationists jump all over the lack of a definitive answer as proof against an old age earth.  However, they are wrong.  Though scientists don’t know for sure why an unconformity occurs, there are plausible reasons.

Most likely, the Pliocene and early Pleistocene were particularly arid.  The rivers in the region dried up and floods were rare.  Floods wash sediment over bones, thus creating fossils, so without fluvial sedimentation, fossil evidence never was preserved from this intervening age.  This dry climate phase may explain why Georgia’s piedmont is almost barren of Pliocene and Pleistocene fossils, though I’m convinced a concerted search of Georgia’s river basins would discover some of the latter age here.

The fossiliferous strata off the coast of Edisto Beach, South Carolina parallels that of the Peace River fossil site and may be due to the same climate phase.  This site too yields both late Pleistocene fossils mixed with Miocene shark’s teeth, so this unlocated Pleistocene strata must overlay Miocene strata, and the ocean currents are eroding both.  At the Ashley River site, also in South Carolina, the Pleistocene fossils overlay even older Oligocene strata.

In the Peace River the fossils are located in an area of only about 84 square feet in sediment about 6-12 feet underwater.  Scuba divers uncovered the fossils.  Miocene fossils are not only found underneath the Pleistocene ones, but they’re intermixed with them and river currents even work them to modern surfaces.  As river currents wash away ancient sediment, they expose these fossils.  Nevertheless, scientists can use knowledge of chemistry to discern the difference in age between Miocene and Pleistocene fossils.

Scientists analyze the ratio of rare earth elements within the fossils.  Rare earth elements are a family that aren’t particularly rare but consist of few a layman would know.  They include 14 in the lanthanide series and 14 in the actinide series.  All actinides, such as uranium, are radioactive.  Lanthanum, cerium, and erbium are some examples of lanthanides.  Rare earth elements exist in small quantities in ground water, and they occur in consistent ratios with each other.  However, these ratios change over time.  When animals drink water they ingest these elements and absorb them into their bones in the same consistent ratios.  Naturally, Pleistocene fossils have ratios of rare earth elements that occured in Pleistocene ground water, while Miocene fossils have ratios of rare earth elements from Miocene-age water.

The list of Pleistocene fossils found at the Peace River is impressive and includes large, warm climate species.

gar

box turtle,

giant tortoise

river cooter

red bellied turtle

rattlesnake

undetermined duck or goose

cormorant

turkey

pampathere (giant armadillo)

glyptodont

eremotherium (giant ground sloth)

Harlan’s ground sloth

raccoon

Florida spectacled bear

dire wolf

jaguar

bobcat

giant beaver

capybara

tapir

horse

flat-headed peccary

collared peccary

stout-legged llama

long-necked llama

bison (antiquas)

white tail deer

mammoth

mastodon

manatee

Miocene fossils from this site are largely marine–shark’s teeth, ray plate teeth, fish bones, dugong bones, and whale bones.  Notably though, 20 specimens from 5 species of three-toed gazelle horses have been recovered here.  Here’s the list:

Cormohipparion plicatile

Cormohipparion ingenuum

Pseudohipparion skinneri

Calippus elachistus

Nannihippus marganui

Three-toed gazelle horses were a common herbivore of the Miocene.  They had a slender build resembling modern day deer.  During the later Pliocene deer likely began to replace them in the ecological niche they occupied, while surviving horses evolved into the one-toed horses of today.

References:

Hulbert, Richard; Gary Morgan, and Ardreas Kerner

“Collared Peccary (Mammalia, Artiodactyla, Tayassuidae, Pecari) from the late Pleistocene of Florida.”

Museum of Northern Arizona bulletin 65

Whitten, Kenneth; and Kenneth Gailey

General Chemistry with Quantitative Analysis

Saunders College Publishing 1984

**************************************************************

Bob Perkins has shipped me an atlatl.  Future blog entries will include an erratic series entitled “Adventures with an Atlatl.”  I’m also planning on entries about Georgia’s Pleistocene Horses, Pleistocene deer, a study of passenger pigeons, and another erratic series detailing my time travel fantasy of living in Georgia’s Pleistocene before people colonized the region.  This includes what technology I would bring back with me, what kind of house I would build, and what foods would I procure.