Tag Archives: taphonomy

Cold case #4. The Graveyard Shift

Read the latest cold case blog @ NCSU’s The Abstract. HERE

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Cretaceous Cold Cases #3: Duck(bill) Amuck

Read Bucky’s new blogpost

Cretaceous Cold Cases #3: Duck(bill) Amuck

@ THE ABSTRACT

Taken from the blogpost:

This is the third post in a series called “Cretaceous Cold Cases” in which the science of taphonomy, or prehistoric forensics, is explained by fascinating cases from the files of Terry “Bucky” Gates, a research scientist with a joint appointment at NC State and theNorth Carolina Museum of Natural Sciences.

 

Chomp or be Chomped, Part II

Research & Collections

Lisa Schultz is bursting at the seams with excitement when we walk into Siemens Training and Development Center in Cary with our box of fossils.  Since early morning, she’s been in this room testing the CT-scanner’s capabilities with a material that is quite a bit different than your average human body—a rock.  Lisa’s “patient” is not just any rock, but a rather pretty hand-sized specimen with veins of crystalline quartz that her daughter found outside a couple of days before our visit.  “Try this out mom,” she told her as she handed it over.

I met Lisa and the other incredible folks at Seimens this past March, when I came to “Take Your Kids to Work Day” to talk about new research on dinosaur fossils (my day job).  After my presentation, Lisa pulled me aside and told me about a new dual energy scanner that the Center had, with a…

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Chomp or Be Chomped, Part I

Research & Collections

With one of the most powerful bites on the planet, crocodiles reign as the king of chomp.

Scientists from Florida State University have measured the force of a crocodile bite at nearly 3,700 pounds.  That’s a little less than the weight of a Dodge Charger balanced on a number 2 pencil.

But if there’s one natural law even a croc can’t break, it’s eat or be eaten….

Two months ago I got the itch to go exploring (a chronic disease-process for paleontologists).  Lucky for me, my colleague and long time curator of paleontology Vince Schneider had a fix.  He was planning a day trip to hunt for the remains of ancient animals that lived and died in the lakes of North Carolina during the Triassic Period, some of which looked a heck of a lot like modern crocodiles.

After assembling a team of paleontologists and volunteers, we hit the…

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“Elementary my dear Watson.”

Thanks to awesome shows like “Matlock” (does anyone remember this show?), “Law and Order”, and “CSI” we all know the routine that police investigators follow when examining a crime scene.  Find the victims, gain personal/demographic information, carefully sweep the crime scene for clues left by the perp, run evidence through fancy glowing machines in dimly lit club-esque police laboratories, then nab that killer.  Easy enough, huh?

Honestly, investigating wildlife scenes is almost exactly like that…we don’t actually catch the animal that killed the other animal.

A large dead elephant. Unlike most of our other carcasses, this animal died from humans. Still, the information gained from the fresh carcasses was awesome for seeing the first stages of carcass scatter, especially on a beast this large.

Our purpose investigating skeletons in the Okavango Delta was to determine what happened to animals from the time that they died until we arrived at that scene.  And every skeleton we find, we will revisit on every trip to see how the bones may have changed over time.

First, after the death, what happens?  There have been great studies where scientists watch a dead animal bloat as their insides fill with the gas of the bacteria that are decomposing the body from the inside out.  If left unharmed by scavengers, the body will eventually rupture (no, I will not show a picture), and trust me, you don’t want to be near a body that does…it really stinks!!

Most often scavengers find the carcass and begin pulling meat away.  Different scavengers feed differently, and most all of the skeletons that we find are scattered over large areas, hundreds of square meters.  Smaller animals are consumed in one sitting by a single animal or one group so remains may not be as spread.

This male impala died less than a month before we found it, at the teeth and claws of a leopard. Most of the body was found under some scrub nearby, which is a big clue to a leopard suspect. Image by Lindsay Zanno

The bite marks left on the bones tell us who was eating what parts of the skeleton.  Lions, hyenas, and vultures all leave very specific breaks and scratches on the bones because of feeding styles and the tools they have in their mouths.

Elephant shoulder blade eaten by hyenas.

So we have a body, we have the weapons of destruction, what next?

Time of death…

this can be trickier to determine.  With a fresh carcass it is not that difficult, but the further away from the time of death the larger our error becomes.  The easiest carcass we found was a leopard tortoise that died the previous night.  We know this because one day the shell was not there on our drive, the next day it was.  Yet, as years go by more and more evidence is destroyed, but that destruction can be a great clue.  See, bones crack when exposed to the sun, and the pattern of cracking estimates the time of exposure.  So we can determine if a skeleton was laid down up to 15 years prior!!

This bone has been on the surface for probably at least a decade. Most of the outer bone is gone, cracks run all over and through it, and the edges have been rounded, they are not sharp as in a new break.

The killer.  Sometimes we know what killed an animal because our guides saw it happen and can tell us.  Or there are clues such the placement and size of carcasses that tell us leopards versus lions were the culprit.  But a lot of times we can’t be sure.  Once multiple animals begin feeding on a carcass bones get scattered and bites overlay one another.  Still we try our best to determine patterns of predator behavior.  Changes to the way predators feed can be wonderful indicators of ecosystem health.

Finally, game trails, or animal highways, can be a terrible disrupter to bone sites.  As animals walk through a bone site they kick bones around, break them into pieces, or push them into mud.  All around causing us grief.  It was interesting though to see so many carcasses along game trails.  Predator killing behavior?  We need more data.

These large tracks are from an elephant that used a game trail through which a giraffe skeleton was found.

Lots of other information can be obtained from bone sites to help us understand the lives of the animals, including DNA sequences, stable isotopes revealing diet and travel of the animal, and amino acid decay to help time death.  We hope to pursue many of these in the future on our quest to breath new life into old bones.

Back to Africa (while the Utah team is out of civilization)

The Utah team is in an area of the state called Mussentuchit Flats looking for dinosaurs about 98 million years old.  There is nothing at all out there except lots of rock with dinosaurs!!  Cell phones are useless, which is one of the great things about paleontology field work every now and then…to go somewhere no one can reach you.  Communing with prehistory and yourself actually is healthy.  But the lack of showers gets old after about 10 days.

So while we all wait for the next field update I wanted to fill in a little more information about our trip to Botswana.

Conversations about my research trip to Botswana usually went something like this:

“Oh, you are heading to Africa!?  That’s exciting.  What kind of dinosaurs are you looking for?”

“Well, none.”

“None, then why are you going?”

“I am looking for dead animals.”

At this point their face would crinkle into a funny contortion of disgust at the thought of a dead animal, and smoke would arise from their ears as they tried really really hard to figure out why in the world anybody would actually want to find a dead animal, let alone as many as humanly possible.

The answer is really quite simple.  That is…because everything in the fossil record is dead.

Well DUH!!  But really think about that.  If everything that we are studying as fossils are dead, all of the experiences and history that each of those animals led is barely transferred to their fossilized remains.

So the best way to tease out every ounce of information about ancient life is to understand exactly what types of information can be preserved by studying modern dead animals.

The main purpose of this trip was to first find, map, and detect any patterns in what bone sites looked like.  We did not have armed guards with us on this trip, and the one short walk that was taken through a savannah felt like a literal death march because our guide spotted tracks from a pride of lions that passed through only a few hours earlier.  Therefore, most of our carcass prospecting was from the vehicle.  Nonetheless, we found over 30 carcasses, some over 10 years old.

And our preliminary findings are positive.  It seems that giraffe carcasses are found where the giraffes live, as well as the water buffalo (these animals don’t live in the same habitat).  Elephants are just everywhere.

Our next goal is to walk miles across the Okavango Delta to find even more carcasses.  Ultimately, our data can be used to assess conservation efforts, changes in populations, and predator behaviors through time.

Tomorrow, I will talk about the forensics of a carcass site…

–Bucky Gates  Earth Then and Now

A Killer Bite

When I cracked open the fresh binding on my senior yearbook an eon ago, I came face to face with the infamous superlatives list, bestowed (wittingly or unwittingly) upon various graduating members of our senior class.  Nicest Eyes, Best Dressed, Most Likely to Open a Gas Station… the list was thoughtfully crafted.

After a few days in Africa observing living animals and taking data off the dead, it occurred to me that if there is one animal in Africa that deserves the award for Best Bite, it’s unequivocally the hyena.

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A killer smile? (c) Arno & Louise Wildlife.

The hyena gest this honor, not because it has the strongest bite—that record goes to another African native, the crocodile—but because it is an equal opportunity lender of mandibular destruction.  Or to put it another way, a hyena doesn’t particularly care what it lends its jaws to.  A hyena is no gourmand.

Time and time again, we found evidence of hyena feeding.  It got to the point that when we approached a carcass the first thing that would run through our mind was: lets see what the hyenas left us this time… But the truth is, it was awe inspiring to see the damage hyenas are capable of inflicting with their teeth.

On every skeleton we found places where hyenas had gnawed off thin parts of bones entirely, such as the shoulder blade or hipbones.

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Hyenas love to chomp on thin bones. Check out the tooth marks on this elephant shoulder blade.

They also appeared to be fond of chewing off the faces of elephant skulls.

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The face on this elephant skull has been chewed off by hyenas.

We even found scat (droppings if you prefer) containing small bones that were swallowed whole by hyenas.

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Hyena scat contains whole bones and turtle shell.  Who needs to chew?

By far the wickedest evidence of hyena feeding was a turtle skeleton we stumbled across in the Kazakini area.  The hyena had taken a young female leopard tortoise up in its jaws and bitten half of it clean off, right through the shell, no finesse required.

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This female leopard tortoise had a bad day.

After all that, I thought I had a handle on the wreckage inflicted by the hyenas.  Boy was I wrong.  Laying in our tent one night I was startled awake by series of hideous sounds—the deep, desperate howls of a large antelope in its death throws overprinted by the frantic, murderous yips and cries of a whole pack of hyenas echoing like a twisted symphony across the grassland.  Then suddenly like the fall of a black curtain, there was only dead silence.  It was enough to make your blood run cold.

Next day we followed the footprints of the successful pack as they walked 50 feet from our campsite.  For a moment the thought of following them to the kill site swept through my mind, but it was quickly followed by the memory of lunatic laughter.

I quickly came to realize I preferred studying the more distant aftermath of the hyena.  Perhaps some things are best left to the cover of night.