Who Got to Mastodon First? Ice Age Wolves, Bears, or Man?

The Morrow County, Ohio, Cedar Creek Mastodon, might have met this fate, its dead carcass scavenged by dire wolves and other predators such as bears and saber-toothed "tigers", not to mention vultures.  This 1911 illustration  of dire wolves fighting with the tiger in the  LaBrea Tar Pits of California is in the public domain..

Life wasn’t easy in the Ice Age, so it shouldn’t be surprising that it’s beginning to look like Ohio’s Morrow County Mastodon might have been torn apart by a pack of Ice Age wolves.

We know that there was at least one wolf that bit into the mastodon’s bones because the excavation uncovered forensic evidence left behind by the guilty party—a canine tooth embedded in the bone.

There were several species of Ice Age wolves, but the “Dire” wolf  is the likeliest suspect because it depended on scavenging dead bodies more than killing, especially in the case of big game.   Although it weighed about 25 percent more than modern wolves, it was slower than other Ice Age wolf species, so it resorted to hunting in packs and killing slower moving animals like the mastodon or scavenging any corpse it stumbled into.

In the most complete report to date, to the volunteers participating in the dig, excavation leader Nigel Brush said he and his colleagues are beginning to wonder if the mastodon might have died of old age and then been eaten by the Dire wolf and other scavengers.

But they have not discarded the original hypothesis—that the mastodon was killed by Paleo-Indians   and butchered.  In that case, the scavenging was done after the men were through with the carcass.

Brush is an associate professor of geology at Ashland University in Ohio.

Brush reported that Brian Redmond , head of archaeology at the Cleveland Museum of Natural History, will have the bone with the embedded wolf tooth X-rayed to get a better view of the tooth.  He also wrote that, “The mastodon bones contain an abundance of gnaw and puncture marks from predators such as wolves and bears.  Among the bones of the mastodon, we have found a tooth (an incisor) and several fragments of leg bone that appear to be from some other Ice Age herbivore (perhaps a musk-ox or stag-moose ?).”

It seems to me that the scavenger hypothesis arose when Brush learned, from geological studies being done at the site, that the broken bones found in the excavation site had been carried there by water flowing from upland of the site, farther from the bog that would have made a natural trap-and-kill site for Paleo-Indians.

Brush also cited the fact that only two possible man-made cut marks on the bones have been found so far, leaving open the possibility that those cuts are not the work of human tools after all.   And most of the flint flakes found were the result of natural weathering and frost or from being washed into the excavation site, rather than from man using or making flint weapons or butchering tools.

But, Metin Eren,  an expert on lithics, the study of the human use of stone for tools, came to the lab at Ashland University and found that about a  the dozen of the flint pieces were possibly worked by people, so a few of the flakes will be sent to another lab for further analysis for blood and protein residues and edge wear from butchering.

Nick Kardulias, another lithics expert, will be doing a more detailed examination of the flint pieces and soil cores recovered from the site.  Kardulias and his students from the College of Wooster  in Ohio have been helping with the excavation along with students from Ashland University and other universities.

Dueling Hypotheses:  Man or Wolf?

He said the only way to decide between the two competing hypotheses is through the lab analyses that will continue through the winter at Ashland University.  He said that one of the critical pieces of evidence to support the Paleo-Indian kill hypothesis would be if the mastodon bones are found-- through carbon-14 testing--to be between 16,000 and 10,000 years old, when Paleo-Indians and mastodons co-existed.

Brush’ report included a Florida lab’s carbon-14 test results on samples taken from the bottom and top of the bog near the excavation site:  Plant material taken from the top of the bog dated to about 11,200 years ago,  while a wood sample from the bottom of the bog was about 12,500 years old.
Another critical piece of evidence to support the kill/butchery site hypothesis, he wrote, would be if they found mastodon blood and protein residues on some of the flint pieces they found that appeared to be used to butcher.   A fourth piece of critical evidence would be confirmation that the possible cut marks on two mastodon bones “are indeed cut marks.”

Brush discounted speculation that some of the rounded stones found near the bones were used to hammer bones to crush them, saying that the stones could just be one of the many cobble stones found  in the natural stone-and-gravel deposits below the excavation site.   He reported that, “We have washed dozens of these cobbles in the lab and have yet to find any fresh surface alteration that we could unequivocally equate with human tool use.”

Occam’s Razor

At that point in his report, Brush wrote that “Occam’s Razor is often quite useful in science:  The simplest explanation is usually the best explanation.  Given the highly battered condition of the cobbles thus far recovered from the site, natural weathering appears to be a much more likely explanation than human utilization.”  He showed a number of the possible hammerstones and other possible stone tools to several other professional archaeologists and all agreed  with Brush.

Brush also cites another axiom from his scientific experience:  “Extraordinary claims require extraordinary evidence.”

As part of this search for strong evidence, Greg Wiles, professor of geology at the College of Wooster, will submit two charcoal samples for carbon-14 dating to the same Florida lab that dated the bog samples, to see if the soil layer where the mastodon bones were found are in the same age range as the bog.  And, Redmond will submit a collagen sample, from one of the four mastodon teeth found, to the Florida lab for carbon dating--hoping there is enough collagen present to do the test.   Earlier this fall, Redmond had submitted a thoracic vertebrae from the Morrow County mastodon, but heavy weathering had removed too much collagen for carbon dating to succeed.

Brush’ report also said that Gregory McDonald, a bone specialist and senior curator of natural history at the National Park Service in Fort Collins, Colorado, might have time to visit the Ashland lab to identify some of the mastodon bones, when he speaks on December 12 at the Cleveland Museum, on "The Snowmastodon Project" .

Note:  What I call the Morrow County mastodon is officially called the Cedar Creek Mastodon, for the creek that runs near the excavation site.  Also, I have a website where I post information and photos on archaeology finds as well as all other aspects of Nature and natural history.  I began this blog and website to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.  All of my writing is done on a volunteer basis.

Fragments of a  leg bone found at the Cedar Creek Mastodon Site could be that of the stag-moose, possibly another victim of the bone-crushing teeth of the Ice Age dire wolf.  (1912 illustration in public domain.) 

Mastodon Dig Turns to Lab for Answers

A look at the Nov. 9, 2014 mastodon dig.  It's likely that some or all of the mastodon bones were washed into the excavation site from upland drainage thousands of years ago.  (Photo by Don Comis)

You can see how cold it was on Nov. 9 by the winter clothing worn by volunteers.  (Photo by Don Comis)

As the search for mastodon bones on a soybean farm in Morrow County, Ohio, winds down before winter, the work shifts to a lab at Ashland University where the excavated materials will be analyzed to decide if it’s worth continuing the excavation in the spring.

Excavation leader, Dr. Nigel Brush-- Ashland University associate professor of geology--wrote in an e-mail answer to my questions, that the lab tests “will provide the final answer” as to whether the mastodon was killed and butchered by Paleo-Indians, as it appears.

Right Site?

Even if the answer is “yes”, the next question is whether the excavation site is the butchery site.  Brush wrote that, “Based on the geological work that is being done at the site, it is appearing more and more likely that the bones were brought to their present location by a debris flow from a site at a higher elevation. “  He added that an upland kill and butchery site doesn’t make as much sense as the current excavation site, which is right near the remnants of an ancient bog where the animal could have been trapped in the soft sediment by its weight.

The bog traces back to the Pleistocene era when it was a muddy glacial lake.

Students from Ohio’s Wooster College’s Climate Change class sank a probe more than 20 feet into the mud, gaining a record of environmental change over about the past 15,000 years.   Brush said, “They also found possible evidence for an old preglacial stream channel running through the bog."

Discovering the Ice Age

Students from Brush’  'Discovering the Ice Age” class are also among the volunteers on the dig.  

Since the skeleton parts found so far are very crushed and shattered, the focus of the excavation shifted after the first month, from recovering a complete skeleton for exhibit, to finding evidence of Paleo-Indians killing and butchering a mastodon.

Brush’s e-mail to me continued, “We have ample evidence from Ohio and surrounding states that Paleoindians were present during this time period.  Butchery sites are not as common, although their number is steadily growing (due to the work of Dan Fisher at the University of Michigan, and other archaeologists).

Paleo-Indian (also written as "Paleoindian") is the term for the first people to arrive in North America, about 16,000 years ago, near the end of the Ice Age.  The website www.Indians.org says that, “Their name, Paleo, actually comes from the Greek word “palaios,” meaning ancient.”

Tools, such as flint scrapers, used to possibly butcher the mastodon are being sent to another lab for DNA analysis to test for mastodon blood.  At the Ashland lab, bones and other materials are being power washed with water and examined for cut marks made by butchering tools.

Scavengers

Brush wrote, “There are a lot of gnaw and bite marks on the bone”, suggesting the possibility that the mastodon merely died of old age, its corpse eaten by scavenging animals.  But, it’s also possible that the scavengers were just mopping up what was left after the Paleo-Indians butchered it.

On Nov. 9, volunteers found another possible hammerstone, a large round stone used to as a hammer or maul to crush things.  Amateur “surface hunters” identify hammerstones by the pecks or pockmarks caused as the stones are pounded on things.   The latest hammerstone was found in the same plot where at least one other hammerstone was found.  Volunteers also found possible vertebrae on Nov. 9.

We also found more pieces of flint and fragments of bones, including small pieces of tusk.

Other items found since the dig began include possible leg bones, ankle bones, rib bones, jaw bones, wrist bones, and all four lower teeth of the mastodon.   And we found pieces of flint brought to the area by man from other parts of Ohio as well as pieces of charcoal that could have come from fires used to cook parts of the mastodon.  A possible fire pit was also found.

As far as I know, the only proven weapon found was a tiny projectile point (a “Merom Expanding Stemmed point “)—a Stone Age spear or arrow head—that belonged to Native Americans who arrived long after the mastodon was extinct.  While the mastodon dates back to beyond 8,000 B.C., the projectile “only” dates to between 1,600 B.C. to 810 B.C.

Mastodon On Its Last Legs

An analysis of the mastodon’s lower four teeth by volunteer Scott Donaldson showed that the mastodon had lived to a ripe old age that likely made it more vulnerable to predation by man or beast, as explained in my previous blog.  Donaldson led the work on restoring and preserving the teeth and served as one of the crew chiefs during the excavation.

In the fall of 2013, a soybean farmer found two of the teeth, two feet apart, after they were unearthed when a ditch was dug to lay drainage pipe.  This triggered the excavation which began Aug. 23, 2014.

The Nov. 9 dig was planned as the last dig before winter, but Brush later said that, weather permitting, he would schedule one more dig, after the weekend of Nov. 15-16.

Note:  I also have a website where I post information and photos on archaeology finds as well as all other aspects of natural history.  This blog and website began to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.

Morrow County Mastodon Site May Yield Rare Evidence of Paleo-Indian Involvement

Big mastodon bones being uncovered last Saturday, observed by Dr. Brush.  (Photo by Don Comis)

For a change, there were too many volunteers last Saturday, but it was a productive day with finding of possible flint tools near bones with possible cut marks, changing the dig's working hypothesis to a Paleo-Indian mastodon kill and/or butchering site.  (Photo by Don Comis)

In his September 24 e-mail report on the results of the Cedar Creek Mastodon site excavation in Morrow County, Ohio, on September 20, Ashland University’s Dr. Nigel Brush said, “The discovery of clusters of bones in association with some large flint flakes last Saturday, as well as possible cut marks on one of the bones…”  leads to “our present working hypothesis… that this site may be a Paleoindian [Also spelled "Paleo-Indian"] kill and/or butchery site.  This changes the goal of our excavation.  Instead of   trying to recover large bones from the mastodon skeleton, we will primarily focus on recovering evidence to validate our hypothesis that this is a human kill/butchery site.  Many mastodon sites have been found in Ohio and surrounding states, but only a few have good evidence for human interaction.   Therefore, we must change our excavation methodology….Our site has the potential to be rather significant, if we follow proper scientific procedures and are careful in our work.”

The changes include:

·         “Since we want to show the association between bones and possible flint tools, we must leave the bones and flint flakes/tools in place when we find them in undisturbed soils…” ;

·         Not touching flint flakes or tools “since we will be sending these off for blood residue analysis and oils on your skin may negate the analysis…”;

·         “Since we will be looking for additional cut marks on the bone, we must be very careful not to scratch the bones when exposing them.”

·         “Floors of excavation units must be kept flat so we can see what materials are in association at each level. Take each 10 cm level down in 5 cm (2 inch) stages.  In other words, take the whole unit down 5 cm. see what is showing up and record if necessary, then go down the other 5 cm.”

·         “…the final removal of bones, flint flakes/tools, and charcoal samples from excavated levels” will be supervised “to insure that they are properly handled, labeled, and stored.  Materials removed from these assemblages will be stored in separate containers from the regular excavation and screening bags…”.

The reason for these changes is that the new working hypothesis makes it important to document what materials are found near each other, as evidence they are related.   Flint flakes or tools  found near bones can be evidence that Paleo-Indians killed the mastodon at this spot and/or butchered it there.   Charcoal nearby could indicate a fire built by the Paleo-Indian hunters.

Paleo-Indians are prehistoric Native Americans that are generally thought to have arrived in North America from Asia at the end of the last Ice Age by crossing a vast ice and land bridge over the Bering Strait.   They were in Ohio during the time the mastodon being excavated probably died, about 13,000 years ago.  Some have blamed these hunters and a warmer climate for the extinction of mastodons.

Dr. Brush also said that, “When we first began excavating this site, we thought most of the mastodon skeleton might remain undisturbed, except for the damage caused by the backhoe during the digging of the drainage ditch.  That scenario is now much less likely since we are recovering fragmented mastodon bones from various parts of the body.  The skeleton could have become disarticulated by the activities of Ice Age predators, or by human hunters. “

But the discovery last Saturday of the large flint flakes near bones with possible cut marks led him to focus on the human hunters, at least for now.

"Discovering the Ice Age" Students Volunteer

Last Saturday’s excavation was in the fourth week of the mastodon dig and we had 62 volunteers, including 8 students from Dr. Brush’s  “Discovering the Ice Age” class, 12 students from Ashland’s  Geology Club and the club advisor, and 7 students from the University of Toledo. 

There were so many volunteers that I couldn’t find a spot to dig so I ended up sifting dirt all day, which was fine with me.  I shared a sifting screen with two novice students and another novice, the wife of an experienced volunteer.

Boy, did I feel great after finding two small pieces of the mastodon’s ivory tusk, before the other volunteers joined me.  I had learned the previous week to identify bones.  This week I learned to identify many tusk pieces because they tend to look like part of a wooden matchstick.

I had brought one to an experienced volunteer and he identified it as a piece of tusk.  When I found a similar piece I identified it as a piece of tusk.  It made me feel like an expert.  And when the complete novices joined me, they were asking me to confirm "bone or no bone" on their finds.  Soon they were finding bone after bone as well.  It was probably because the soil we were sifting had a lot of bone fragments, but it felt nice for them to say I was a good teacher when I complimented them on their finds.

A 300-million-year-old brachiopod fossil was a mere distraction during the mastodon excavation last Saturday.  (Photo by Don Comis)

  

One found a fossil and took it to her geology club advisor and he identified it as a 300-million-year old brachiopod.  It was exciting for us but of no interest to the mastodon diggers because they are only looking for bones or other things are about 13,000 years old, about the time the mastodon lived.

More big bones were emerging in Unit 14, which has been excavated to the 12- to 16-inch depth.  A new set of bones could be a wrist of the mastodon, but it hasn’t been completely unearthed yet.

The work continues this Saturday, September 27, but I’ll probably miss it because I had an earlier commitment to collect prairie seed at Guy Denny’s prairie in Fredericktown.

As a sidenote, Dr. Brush added that the University of Michigan has developed a 3-D image of a mastodon that we can use to identify the bones as we find them .  It can be seen here.   It is great, allowing you to rotate the skeleton in any direction, including upside down to see inside the rib cage. And  by clicking just right on a particular bone, you can examine the actual bone close-up and rotate it too!

The story behind the creation of this image by using new technology and scanned images of mastodon bones in the collection of the University’s  Museum of Paleontology is here.  It includes a nice video.

Dr. Brush also said that Brian Redman from the Cleveland Museum of Natural History will be visiting the site on Saturday, as well as a reporter from the Columbus Dispatch.

Note:  I'll try to add more of last Saturday's photographs to my "Mastodon Dig" slideshow on my website.