Season 1 Transcript

“Beecher’s Trilobite Bed” Transcript and References

(The following is the script used for “Beecher’s Trilobite Bed” and closely matches the final episode product)

<sounds of nature which slowly fades>

For eight years, William Valiant, a one-armed carpenter and fossil enthusiast had been looking for the find of a lifetime.  He and his half-brother, Sidney Mitchell, would spend their days off in the countryside, near their home of Rome, New York, looking for a particular fossil.  It started from a chance find, when William found an odd fossil at Six Mile Creek in 1884.  It was a golden leg of a trilobite, an ancient sea creature that looked like a squashed centipede.  Up until then, no one knew what a trilobite’s leg looked like.  This leg was amazingly preserved, unlike what William had ever seen before, and he was enamored by its design.  He knew that if he could find the rest of the fossil, he might find something even more remarkable, their antennae.  Paleontologists, up until then, had thought trilobites had antennae but the lack of fossilized evidence meant that this was mere postulating.  William knew that if he found the trilobite, antennae, legs and all, he would be making history.

William Valiant standing next to a Mastodon in Rutgers Geology Museum

So for eight years he and his brother would search for these fossils.  Again and again, nothing.  Finally, he found the fossils; they were buried deep along a hillside and nestled within a layer of shale just 4 cm thick that was practically indistinguishable from the meters of rock that surrounded it.  Yet within these 4 cm of rock were some of the most amazing fossils found by that date.  These trilobites were golden as if touched by Midas himself.  They were preserved in stunning detail with their many legs in neat rows and their original 3-dimensional body only slightly squashed by the layers of rock above it.  And there, in miraculous detail, were the thin antennae arching like a whip.  He had finally found his white whale, or in this case, his golden trilobite.  Few other trilobite fossils can match the level of stunning quality and detail of these golden trilobites.  But how did this happen?  Why are the trilobites preserved so perfectly?

In this episode of Fossil Bonanza, we will answer these pertinent questions and dive into the wonderful Lagerstatte of Beecher’s Trilobite Bed.  Let’s take a look!

<Music intro>
History of Beecher’s Trilobite Bed

Hello and welcome to Fossil Bonanza!  My name is Andy Connolly and this is a podcast where we look at unusual fossil sites around the world called Fossil-Lagerstätten.  In our first episode, we talked about the history of paleontology, how it can be very hard for a critter to become a fossil, and the different types of Fossil-Lagerstätten.  This is our second episode and the first to focus on a particular fossil site.  For our first episode, I wanted to focus on something that was small but impressive and I thought Beecher’s Trilobite Bed fit the bill.

If you were to step back to upstate New York about 445 mya, you would not be strolling through a cool, temperate forest but swimming in a sub tropical sea.  It is the late Ordovician Period and the world is very different than it is today.  Dinosaurs, reptiles, mammals, or amphibians haven’t evolved yet.  In fact, life on land is restricted to just a few small colonizers of bugs and moss.  The sea in New York hosts a variety of weird and wonderful creatures who thrive in this world.  One of which are the trilobites; a very successful ancient group of bug-like animals who could be found in every sea across the world.  And on one fateful day, these trilobites and their ecological partners, would be preserved in a freak accident that would make them one of the best fossil sites in North America.

Beecher’s Trilobite Bed, found within the Frankfort Shale of the Utica Formation, is a Konservat-Lagerstätten, a Lagerstätte with very high quality fossils.  There’s not a lot of fossils here but dang are they not just outstanding!  The fossils are made of pyrite which gives them a most luxurious sheen compared to the more drab and dull-looking fossils you may see in museums.  This gives the golden fossils a very sharp image contrasting the surrounding shale which is a dark gray, almost black color.


You may be thinking that Beecher was the scientist who discovered the these pyritic fossils.  Well, although Charles Beecher was instrumental in the site’s history, he wasn’t the first to discover it.

Like a lot of famous fossil finds, Beecher’s Trilobite Bed was found by luck, persistence, and an amateur.  As introduced in this episode, the fossils were found by William Valiant of Rome, New York.  While walking along Six Mile Creek, he found a chip of shale with trilobite appendages on it and immediately recognized its importance.  As we’ll get into later, trilobite legs are rarely preserved in the rocks.  Even rarer were fossilized antennae which paleontologists hypothesized trilobites had but lacked crucial evidence to support it.  Valiant recognized the importance of his lucky find and vowed to locate the site that entombs these creatures.  It took him eight years but he and his brother found the trilobite bed in 1892.  Antennae, appendages, and all.

Finding these golden critters was like hitting the paleontological jackpot and Valiant was excited!  He wrote to several regional paleontologists and sent them fossil samples of his instrumental find.  One of them was WD Matthew who recognized their significance and proclaimed in 1893 using the samples as examples that trilobites had antennae. Valiant also wrote to the famous Professor Marsh at Yale.  Marsh referred this information to a man he thought would take a great interest in the pyritic trilobites, a younger colleague named Charles Beecher.  Beecher was Yale’s first invertebrate paleontologist and was Curator of Geology beginning in 1891 (as a side note, an invertebrate is an animal that doesn’t have a backbone like we do such as insects, corals, clams, and worms).   The excited Beecher wasted no time; he took a lease on the land in 1893 and started excavating the fossils that same year.  When Beecher found the trilobites he excitedly wrote to Marsh “I feel quite well satisfied now with the results of this trip, and think we can nearly control the antennae business. I look forward with pleasure to working up the collection.”  You see?  I wasn’t kidding about the antennae, it was like the paleontological equivalent of seeing dollar signs.  

Dr. Charles Emerson Beecher

Upon fossil extraction, Beecher prepared the 4 cm long trilobites by experimenting with different tools.  When it was quite apparent that a simple chisel and hammer weren’t going to cut it, he tried acid which ended up dissolving both the stone and the fossil.  Dental tools worked well but couldn’t uncover the delicate legs very well.  But finally, Beecher found that an eraser with a soft rubber was the best tool as he could rub away the soft shale without damaging the fossil.  It was so refined he could even clean out the spaces inbetween the trilobite legs.  He was so good at it that William Dall of the Smithsonian wrote “aided by his remarkable manual dexterity, mechanical skill, and untiring patience, [he] worked out the structure of antennae, legs, and other ventral appendages with a minuteness which had previously been impossible.”

Beecher’s meticulous preparation, research, and publications on the trilobites is the reason why the quarry is named after him.  He gave detailed analysis of the trilobites’ anatomy and described larval stages of key trilobite species using the specimens.  His artistic reconstructions of a trilobite were so incredible that his artwork was reproduced many, many times in textbooks and brought fame to his quarry.  In fact, before he published photographs as proof, some scientists regarded his drawings as so outlandish that they were unreliable.  They were that game breaking.  Unfortunately, before Beecher could publish more papers on the triobite’s anatomy and family relationships, he passed away at just 47 in 1904.  Thankfully, his student Percy Raymond completed his work in 1920 when he became a professor at Harvard University and Beecher’s work is still available today for all to read.

Image from Beecher (1896)

Beecher believed his quarry, and another quarry that was located just upstream, was completely excavated but attempts have been made decades after his death to confirm it.  This proved difficult as many people had trouble trying to find it.  But in the 1980s the bed was rediscovered by two fossil collectors after carefully studying old photographs of Beecher’s site.  The site has since been further excavated by paleontologists from the Smithsonian, American Museum of Natural History, and the Yale Peabody Museum and continues to be a treasure trove of fossils to this day.

Trilobites and their Fossilization

So, it may not come as a great shock to you that most of the discovered fossils of Beecher’s Trilobite Bed are trilobites with just a few creatures from other animal groups.  So…what is a trilobite exactly?

The Life Of The Ordovician. Continued | Trilobite fossil, Trilobite, Fossils
Trilobites in all their wonderful forms

The trilobite is probably the most iconic fossil just behind the ammonites (the spiral shaped fossil).  It’s more than likely you have seen one before and there’s a good chance that if you have a fossil collection you have a trilobite.  Trilobites kind of look like pill bugs but a bit wider, a more prominent head, and generally larger.  The name “trilobite” means “three lobe” in reference to their general body plan.  They have an axial lobe, which runs centrally from their head to tail, and is flanked by two pleural lobes that make up their sides.  Despite the great difference in size and shape among trilobites, they all have these three lobes.

Trilobites are in the arthropod group of animals which contains critters like insects, spiders, crabs, and basically anything that has a hard exoskeleton and jointed legs.  A lot of people like to compare trilobites to the modern horseshoe crab which I’m a bit uneasy at.  True, horseshoe crabs are marine and they’re arthropods but they’re not descendents of them; they are as closely related to them as they are to spiders.

In fact, trilobites are basically their own group of arthropods!  Broadly speaking, there are five groups of arthropods; the crustaceans (which include lobsters and crabs), the myriapods (centipedes and millipedes), the chelicerates (spiders, scorpions, and horseshoe crabs), the insects, and finally the trilobites.  I have read estimates that over 20,000 species have been named so far which is incredible.  By comparison there are just over 5,000 species of modern mammals.  Indeed, trilobites were a very successful group of animals.

You may have noticed that among the five arthropod groups only trilobites aren’t alive today.  Trilobites, unfortunately, are currently extinct.  They evolved very early about 521 million years ago and rapidly flourished.  However, as time went on they began to die off and their numbers were greatly reduced following many extinction events.  The greatest extinction of all time, the Permian Extinction, was the one that wiped them out 252 million years ago.  So they lived for about 270 million years which is a fantastic achievement.  (As a frame of reference, dinosaurs, who appeared after trilobites went extinct, lived for about 165 million years.)  

Okay, so since trilobites are a very common fossil, why do paleontologists make a big deal about Beecher’s Trilobite Bed?  This…is where the story gets interesting!

One of the reasons why arthropods are the most dominant lifeform on the planet is their exoskeleton.  Their exoskeleton is made of mostly chitin which is a rather tough and resilient material.  In trilobites, crabs, and lobsters, the shells are further reinforced by the hard mineral calcium carbonate.  The exoskeleton is the main source of strength and speed for arthropods.  With it, they’re able to exploit environments and fill in roles that may otherwise be left open.

The biggest drawback of the exoskeleton is its rigidity.  Unlike our bones or a shell of a tortoise, an arthropod’s exoskeleton does not grow with the animal as it ages from larva to adult.  Every time it gets too big for its exoskeleton, it sheds it, crawls out of it like some sort of freaky body bag, and allows its new exoskeleton to expand and harden.  This process is called “ecdysis” and the discarded old exoskeleton is called an “exuviae.”  A well known example of this are cicadas who, after they crawl out of the ground like cute zombies, will shed their old skin, unfurl their wings, and begin their wonderful life above ground.  You’ll see their exuviae everywhere, especially when a group of them come out of the ground at the end of their 17 year cycle.


Trilobites go through ecdysis as well!  Paleontologists hypothesize that trilobites start its ecdysis by latching its tail to the bottom of the ocean and wiggling back and forth.  The sides of their head, called a cephalon, would then split wide open and allow the trilobite to escape.  Their exuviae, now completely discarded, could be easily buried by sand and mud and eventually fossilize.  Given that trilobites can sometimes be a foot long, they likely shed their skin at least several times a year.  This means (ready for the mind blowing part?) that a single trilobite can leave multiple fossils of itself!  In fact, most trilobite fossils found in the world are just their exuviae!  Whole species and genera are described from their discarded exoskeleton alone.  It’s honestly quite rare to find the actual trilobite body.

Now remember what I said a moment ago that trilobites use calcium carbonate to reinforce their shells?  That shell’s durability gives it strength to fossilize properly.  HOWEVER, a trilobite’s legs and antennae do NOT have that mineral!  That means they are much softer AND are more likely to rot away before being preserved!  It’s very much like a bird’s feather or a mammal’s hair, if you find a trilobite’s antennae, you found something good.

Now it falls into place.  Why our amateur fossil collector, Valiant, was so keen in finding those trilobite fossils.  When he stumbled upon that shale chip of a fossilized trilobite leg, he knew how valuable it was and why he had to find the rest of it.  Why he had to spend eight years of his life looking for that bed.  To find trilobites that were not just their exuviae but of their legs, and antennae, and anything else that could be preserved in those black layers of shale.

That is the significance of Beecher’s Trilobite Bed.  Not just because they’re golden or preserved in pyrite but because they store the memory of the trilobite itself, body and all.  We know exactly what trilobites look like thanks to those 4 cm layers of rock.  This is why Beecher’s Trilobite Bed is a Konservat-Lagerstätten.

How the Trilobites got Preserved

So how did these trilobites gets preserved?  And why did pyritized trilobites only happen in this very specific, 4cm layer of rock when the surrounding shale layers only have bits and pieces of fossils?

Organisms can become fossils in several different ways but one of the most prominent methods is called “permineralization.”  This occurs when pores inside an animal or plant’s cells are filled with mineralized water; this water can come oceans, lakes, or even rain.  As the water evaporates or moves out of the pores, it leaves behind minerals that were dissolved in the water. The minerals will crystalize and reconstruct the tissue shape of the organism and can even preserve the original organic material.  Petrified wood and bones commonly go through permineralization to become a fossil.  As we progress on Fossil Bonanza, we will return to permineralization again and again and how it affected our Lagerstätten.  

So, permineralization can use different minerals to preserve the organism.  Silica is a really common mineral in permineralization and can be frequently seen petrified wood.  If the animal is preserved fast enough, some minerals work very well to protect soft tissues like carbonate or phosphate.  For Beecher’s Trilobite Bed, the presence of sulfur changes the trilobite into pyrite which is called pyritization.


Pyrite, also known as Fool’s Gold, has a simple chemical formula of iron disulfide and is a very common Earth mineral especially in marine sediment (if you ever go to gem and mineral shows you’ll see these minerals on sale relatively cheap).  I really like pyrite because they’ll grow into these beautiful golden cubes.  Sometimes they’ll have cubes upon cubes and create a stunning geometric shape to them!  They’re very wonderful.  (and as a side note, I love teaching rocks and minerals to my students because they’ll get to see pyrite and debate if they pyrite cube is gold or not which is quite amusing.)

A source for pyrite’s commonality are humble organisms with an intense name; anaerobic sulfate-reducing bacteria.  There’s a lot to unpack here!  Anaerobic sulfate-reducing bacteria.  Let’s break that down.  First, bacteria are single-celled microorganisms that are smaller than our animal cells and can live in all sorts of crazy environments like the hot springs of Yellowstone.  In fact, many bacteria don’t need oxygen to survive.  These bacteria are called “anaerobic” while those who do need oxygen are called “aerobic.”  Aerobic organisms use oxygen to breathe while anaerobic organisms use other molecules instead.  What’s wild is that many anaerobic bacteria find oxygen toxic and can even die from oxygen poisoning!  Okay, so if they don’t need oxygen, what do they use?

Anaerobic organisms can use such molecules as sulfate, nitrate, or iron to produce energy and quote-unquote “breathe.”  For sulfate-reducing bacteria, they use sulfate (which is made of one sulfur and four oxygen atoms) and reduce it to hydrogen sulfide as an end product.  You may have experienced sulfate-reducing bacteria in real life as they’re the source of rotten egg smell or the sulfurous smells from salt marshes.  The hydrogen sulfide is important to us as when it reacts to the sediment’s iron minerals they form pyrite!  (this, btw, is a simplified look at the process and is about as in-depth as we’ll get for our fossil podcast).  

Despite the commonality of these bacteria along with sulfur and iron, the process to turn animals into pyrite is actually pretty rare.  Even then, when pyritization does happen it’s only the animal’s hard parts that are preserved and nothing else.  Only in very specific circumstances can soft-part preservation happen.  So what was it that led to the trilobite preservation?

Before the trilobites came, the sulfate-reducing bacteria were living in an ocean floor with a severe lack of organic food.  We know this because many of the surrounding rock layers had a plethora of fossilized burying organism but that 4 cm layer of rock had nothing, it was an underwater desert.  This was a time when the bacteria were starving. But what the layer DID have was iron and lots of it.  All of this iron and all of these starving bacteria were primed to make our Lagerstatte happen. It just needed one more key ingredient.

That key ingredient came in a flash.  Based on the fossils and the sediment patterns, we can infer that the trilobites were dumped into their current position from somewhere upshore by a turbidity current (basically an underwater avalanche).  We know this for several reasons and the first of which are the trilobites which are arranged roughly parallel to each other. This indicates that a strong unidirectional-moving current carried the trilobites all at once before burial.  This also means that the trilobites were already dead by the time they got buried because otherwise they would have attempted to escape and disrupt their alignment.  Furthermore, the sediment patterns in Beecher’s Trilobite Bed match modern turbidity currents which is quite a smoking gun.  You can see evidence of this in the rock layers as it starts with a heavily eroded base followed by a gradual decrease of sediment size upward due to a weakening current.

As such, we now have all our pieces to reconstruct the scene of the crime.  First, a turbidity current was triggered by some unknown force and swept across the ocean floor. It picked up the trilobites and buried them further downwards.  The shock of the deeper water’s cold temperatures likely killed the trilobites quickly which kept them in place.  Now buried, the trilobites were protected from any scavengers who may tear apart the soft limbs.

The influx of this fresh meat triggered the sulfate-reducing bacteria who immediately went to town on the trilobites’ shells, antennae, and legs.  The bacteria produced hydrogen sulfide which was trapped by the overlying sediment.  The water, rich with iron, seeped in through the trilobites’ pores and reacted with the hydrogen sulfide.  Pyrite precipitated out of the water and replaced the trilobite’s original body, reconstructing it with the golden mineral.  Since the sediment was still loose and non-compacted, the trilobite bodies’ original 3-dimensional form was replaced by the pyrite recreating even their soft tissues and structures.  In a matter of months the reactions ceased and the trilobites laid undisturbed for over 400 million years, waiting patiently to be discovered by William Valiant.

Two Triarthrus

The Trilobites in Beecher’s Bed

Now that we understand how our trilobites got preserved let’s focus on the animals themselves.  What have we found in these rock layers and what can we infer from the fossils?

Although trilobites dominate the fossil assemblage, both in abundance and in notoriety, we see other animals that are typical of the Ordovician period.  These mainly include the clam-like brachiopods and the colony-oriented graptolites.  As these animals make up a small percentage of the fossils, and aren’t particularly special, we will put them aside for now.  Perhaps in a future episode I will talk more about them and their global commonality but for now they’ll just be a footnote for us.

Even among our trilobites there is one species that dominates the rest called Triarthrus.  It’s so abundant it makes up about 85% of the fauna recovered from the bed!  Growing up to 4 cm long, Triarthrus is probably one of the most recognizable species of trilobites in the world thanks to Beecher’s Trilobite Bed.  The original drawings of Triarthrus by Beecher were quickly favored in paleontology textbooks and research papers and they were recreated again and again.  The clean visuals, the many spindly legs, and the long and flowing antennae were easy on the eyes and mind.  If you ever see a recreation of a trilobite, it’s a good chance it’s a Triarthrus.  

Museum Triarthrus Trilobite

The plethora of Triarthrus that make up our death assemblage means we can gleam some juicy information that may otherwise be lost with just the one individual.  For instance, the amazingly preserved legs and gills give us an idea how Triarthrus moved and fed along the ocean floor.  We also have an idea of their overall shape given their 3-dimensional burial with minimal squashing.  However, one of the more incredible things about these fossils are their preserved guts!  Since the pyrite recreated the original structure of the trilobites’ internal organs, we can peak inside them using X-rays and see what they look like.  It’s preserved so well that we can determine a trilobite’s gut is very similar to a crab or spider’s gut.  Isn’t that wild???

These detailed anatomical recreations of Triarthrus are quite useful in reconstructing the overall arthropodal family tree.  Thanks to these remarkable trilobites along with other fossilized evidence, paleontologists infer that trilobites’ closest living relatives are the crustaceans and the chelicerates (who again include the horseshoe crab, spiders, and scorpions).

The abundance of Triarthrus fossils also means we can think about their life cycle.  Adult Triarthrus are very common in Beecher’s Trilobite Bed but what’s notably absent are the juveniles.  Although you can find fossils of juvenile exuviae, just like any other trilobite fossil, their actual bodies are completely absent.  This is also interesting given that only a small percentage of trilobites reach adulthood.  So why is Beecher’s Trilobite Bed so adult-heavy?

Well, based on Beecher’s Trilobite Bed and other Triarthrus fossils found elsewhere, we have a pretty good idea what their lifecycle was like.  After hatching from eggs less than a millimeter long, the baby trilobites would float in the water for a month or so as a suspension feeder.  As they grow older and shed their exoskeletons, they gradually transitioned to a seabed-only lifestyle where they scavenged on carcusses and hunt any small critters they dig up.  Based on their exuviae, it’s likely they lived to about four years of age and probably had an annual breeding season like modern crustaceans.

Given this context, it makes sense why the adults were preserved and not the juveniles in Beecher’s Trilobite Bed.  When the turbidity current came it only affected the adults and not the kids as they were having a good time up in the water column, relaxing, and taking it easy.  Meanwhile, the adults were swept away by the underwater avalanche and died for simply being too old.  This also explains why there’s a notable absence of other sea dwellers as they were above the disaster zone.  Very cool.

Cryptolithus tessellatus
Cryptolithus although not from BTB

There are a few other trilobite species found here but they are quite rare.  One of the more interesting species is Cryptolithus which, unlike Triarthrus lacked eyes!  They had these sensory pits instead which helped them observe the low-light world of the ocean floor.  We also find mainly baby specimens of Stenoblepharum and it’s likely they spent their time on the sea floor before moving up to the water column (basically the complete opposite scenario of Triarthrus).  But like I said, both of these species are quite rare and really, a more accurate name for Beecher’s Trilobite Bed should be Beecher’s Triarthrus Bed!  Hm, probably for the best that we stick to the original; it’s a lot more brand friendly!


So as we close our first Lagerstätte-themed episode I want to reflect on the importance of Beecher’s Trilobite Bed.  I think Beecher’s Trilobite Bed is a great example of a Konservat-Lagerstätte because of those amazing trilobites.  The fact that we can preserve the legs, antennae, and even their gut, preserved in multiple specimens is amazing!  We can recreate their life cycle, their feeding habits, and their way-of-life from these precious fossils.  We can also learn more about how Triarthrus, and in general trilobites, fit in the overall tree of life, how they relate to modern animals and, on the flip side, how we can use modern animals to infer about their lifestyle.  And to this day, we see Beecher’s drawings of trilobites as they fill our textbooks and minds of these once bygone creatures.  It’s all just very remarkable and poetic.

As we progress in this series, I have a feeling we will be seeing the influence of Fossil-Lagerstatten, whether subtle or not, come again and again.  The gaps in our Earth’s history are so wide and so thin that any remarkable fossil will give a peak into a world that is otherwise lost.  Their fossils fill museum displays, painted into murals, and make up so many iconic ancient animals that we see on TV and in the movies. 

When I teach my students geology, I sometimes get asked how much money the pyrite is worth.  And my response?  It’s not the financial value that makes it important, it’s what we can learn from the object.  And though the trilobites’ pyritic makeup does make them amazing to behold, what we can learn from them, I would argue, makes them many times more special.  William Valiant knew this as well and it’s what made his eight years of searching for the golden trilobites worth it.If you liked this episode and would like to hear more please subscribe and check out my Fossil Bonanza blog where I post articles and more podcast episodes.  If you have any thoughts or what you would like to learn more og let me know in the comments!  If you also want to read more about Beecher’s Trilobite Bed I’ll include research papers that are free for the public as well as Beecher’s original papers.  One thing that I didn’t mention were the Sulfur isotopes that were influential in the pyritization process.  I’d figured I already went technical enough as is in this episode so I kept it on the lighter side.  And check out the books Fossil Ecosystems of North America  by Nudds and Selden and Exceptional Fossil Preservation by Bottjer, Etter, Hagadorgn, and Tang.  These books talk about Beecher’s Trilobite Bed along with other unusual fossil sites.  Also check out Richard Conniff’s House of Lost Worlds which provided some good insight into the trilobite bed.  Thanks again for watching and I hope to see you again next time!

-Beecher, Charles Emerson. “ART. XXIX.–The Morphology of Triarthrus.” American Journal of Science (1880-1910) 1.4 (1896): 251.
-Briggs, Derek EG, Simon H. Bottrell, and Robert Raiswell. “Pyritization of soft-bodied fossils: Beecher’s trilobite bed, Upper Ordovician, New York State.” Geology 19.12 (1991): 1221-1224.
-Cisne, John L. “Life history of an Ordovican trilobite Triarthrus Eatoni.” Ecology 54.1 (1973): 135-142.
-Cisne, John L. “Anatomy of Triarthrus and the relationships of the Trilobita.” (1975).

Season 1 Transcript

“Introduction to Fossil Bonanza” Transcript

(the following was the script I used for this episode and closely matches the final episode product)

A mother giving birth, a blooming flower, a parasite emerging from its host, a predator gnawing on a bone.  These are moments in life that we can experience sometimes every day.  Yet, these common occurrences are incredibly rare in the fossil record.  Although fossils can illuminate the past like a guiding beacon, they can only tell us so much about our ancient world and its many inhabitants.

Yet every now and then, we experience truly incredible fossil sites that defy expectations and reshape our understandings of the past.  We can discover long-gone ecosystems, observe behaviors locked in stone, and reconstruct the Tree of Life.  These fossil sites are so revolutionary that they upend and rebuild our perception of worlds long past.  They are so remarkable and so rare that these fossil sites have their own special designation, Fossil-Lagerstätten.

Hello, my name is Andy Connolly and welcome to Fossil Bonanza!  This is a podcast that focuses on these amazing fossil sites.  Normally, fossils are found mostly incomplete with just their teeth or other hard body parts preserved.  However, the Earth occasionally blesses us with Lagerstätten which can amass thousands, sometimes millions of preserved fossils in stunning quality.  Birds can be found with their bones perfectly intact and their feathers arranged in a beautiful display.  Flowers are captured in full bloom and leaves look as if they had just fallen from its parental tree.  Even insects entombed in amber have their tiny, delicate hairs untouched. Some of these fossil sites are quite well known like La Brea Tar Pits in California, Burgess Shale in Canada, or Naracoorte Caves in Australia.  Others fly under the public’s collective radar like the Pisco Formation in Peru or the Wuda Tuff Flora in China.  Nevertheless, these sites all contribute vast quantities of knowledge about our ancient worlds and fill in the gaps that would otherwise be empty forever.

It’s incredibly likely that if you are a fan of fossils or paleontology in general you have seen the influence of Fossil-Lagerstätten.  They’re seen in documentaries, movies, and books of all kinds.  Whole parks and World Heritage Sites are designated to protect their fossils.  They’re the reason why we know dinosaurs had feathers and trilobites had antennae.  They spark famous science fiction stories like Jurassic Park and inspire generations of young paleontologists.  Scientists spend their whole career studying just one site and businesses make a living excavating, cleaning, and selling these fossils.  And every time a new fossil site is found it is like Prometheus giving fire to man.  Their importance can not be unstated.

Naracoorte | South Australia, Australia | Britannica
Image from

For season one, I will be looking at five of these amazing sites.  Beecher’s Trilobite Bed, Posidonia Shale, Dominican Amber, Jehol Biota, and Naracoorte Caves.  These sites represent the incredible diversity of Fossil-Lagerstätten.  They all differ whether it’s their geographic location, their time period, their ecosystems, or their preservation method.  We will understand how these fossil sites were formed, its denizens, and their impact on paleontology.

Now this episode will serve as our introduction to Fossil Bonanza.  Who I am, why it’s hard to become a fossil, and an overview Fossil-Lagerstätten.  But!  If you want to skip all that and go right to the good stuff, I already uploaded episode 2 focusing on our first fossil site, Beecher’s Trilobite Bed.  A spectacular site with golden trilobites preserving everything from their antennae to their legs to even their guts!  It’s great, you don’t want to miss out.

As for those of you who want to stick around some more.  Let’s go back to the past.  But not to an ancient past millions of years ago but a recent one.  We’re rowing up to the shoreline of Middle Age Italy and discussing the mysterious origins of the valuable “tongue stones.”  Let’s dive in.

Brief Early History of Paleontology

In the Middle Ages of Italy a particular object known as glossopetrae was highly coveted among elite and royalty.  They were triangular-shaped and embedded in layers of rocks found in great quantities on Malta.  These glossopetrae, translated as “tongue stones,” were believed to be tongue tips of snakes and dragons.  The legend goes that Saint Paul was shipwrecked on Malta and was bitten by an adder.  Understandably peeved, Saint Paul cursed the adder and all the island snakes’ tongues to stone.  As such, these tongue stones were highly valued for their ability to ward off poisons.  Dipping one in a poisoned drink or laying it on a venomous bite will cure the poison.  People would wear these tongue stones around their necks as pendants or sewn into pockets.  Sometimes they were powdered and sold as remedies for diseases like fevers and poxes.  They were a hot commodity.

Small Blessings - Tongue Stone, France
Image from

Then in 1666 the true origin of these tongue stones was deduced.  1666 proved to be a milestone in the history of science as Newton discovered calculus, optics, and gravity at the age of 23.  This very impressive feat overshadowed what some scientists believe was the birth of paleontology or the study of ancient life.

In October 1666, two fishermen caught a shark off the coast of Italy and thought to themselves; this fish is wild!  Let’s show it to the Duke!  So they brought the shark’s head to the court of Florence and showed it to the officials even though the head was partly rotted and very likely smelled notrocious.  Despite the hilariously icky nature of the find, the court’s physician Neils Stensen, also known as Nicolaus Steno, decided to examine this curious finding.  He meticulously dissected it and noticed its array of teeth that jut outwards in a brutal, almost chaotic fashion.  These teeth in fact, looked just like the tongue stones that were all the rage in Europe.  He reasoned this similarity meant that tongue stones and shark teeth were one in the same.

Niels Stensen
Image from

But with this came a question, why are there so many shark teeth and why can you find them in the mountains, the antithesis of oceans?  He reasoned that a great flood buried these teeth under layers of mud which hardened over time and new layers build on top of them.  Eventually, the ocean retreated to expose these teeth to the world.  This formed the basis of Steno’s Law of Superposition, that rock layers on the bottom were older than layers on the top, and it serves as one of the most important laws of geology.

It’s understandable that people didn’t equate tongue stones with ancient shark teeth.  For one thing, it’s not like there are a whole bunch of sharks just walking on the land!  They prefer their oceanic homes.  And in general, paleontology, compared to other sciences, is actually relatively young.  Biology, physics, chemistry, and astronomy had their roots in ancient history but geology didn’t seriously take off until the 1600s.  It wasn’t even until the end of the 1700s that the concept of fossils began to take hold of the science community.  Granted, fossils were repeatedly discovered before by many people over many places over many years but these fossils were thought to come from modern animals or left behind in the Biblical Flood.

Why did it take so long for people to realize that fossils were left behind by ancient creatures?  Well, many European scholars operated under the popular assumption that the Earth formed around 4004 BC as interpreted by the bible.  To our relatively short lives, the Earth appears immutable; quiet and still with the occasional volcano explosion or landslide to spice things up but that’s it.  But by the 1700s creeping doubt set in among scientists that perhaps the Earth was a bit older than that and may have, (gasp!), existed before us!  But economic incentives related to mining reinforced a more rigorous and scientific method approach to geology.  If you want to get rich, you need to read the rocks! 

Fossils were also hard to swallow as they basically went against God’s plan.  The Earth was formed complete and perfect by God so every animal and plant that was formed in the beginning of time still lives today.  The idea that any of God’s creatures could disappear was very hard to compromise.  Thomas Jefferson, who had a keen interest in the sciences, could not believe that his precious mastodon was extinct and wrote “such is the balance of nature, that no instance can be produced, of her having permitted any one race of her animals to become extinct; of her having formed any link in her great work so weak as to be broken.”  TJ even hoped Lewis and Clark would find the mastodon, and other weird creatures, as they journeyed west to the Pacific Ocean.  Alas, that wasn’t the case and I can’t blame him.  That would’ve been soooooo cool if North America still had mastodons and other ancient behemoths.  (This is the park ranger side of me talking but I sometimes wonder what our national parks would’ve been like if the American Lion, elephants, and giant beavers were still with us.)

But I digress, extinction, and in general paleontology, was slowly accepted in the late 1700s for two principal reasons.  First, paleontology is, well, it’s kind of a weird offspring of biology, the study of life, and geology, the study of the Earth.  It helps to have your feet in both fields to understand it.  Take the mammoth for instance, if you found its fossil in France before the 1700s, you might’ve thought it was a skeleton of a legendary creature like a giant.  If you had some biological background, you could infer it was an elephant that died during an Ancient Roman invasion or was washed ashore from the Biblical Flood.  Sure maybe the tusks are bigger and the teeth look off but its looks pretty close…eh…it’s probably an elephant.  So the lack of geologically important knowledge that our world is very ancient and very old meant we had a hard time grasping the significance of these finds.  Thankfully, our understanding of biology and geology and other sciences advanced rapidly at this time which we call the Scientific Revolution.  The knowledge was there, we just needed a push.

That push came from the advancement of travel technology, of all things.  Ships sailed faster, food storage got better, and maps became more accurate.  The world was being discovered.  Animals and plants of all kinds were collected and studied from across the seas.  Museums were taking off showcasing the wonders of the world.  Whole families of birds, amphibians, and mammals were studied and proclaimed.  It was like the scientific equivalent of an info dump.

Georges Cuvier - Scientist of the Day - Linda Hall Library
Image from

This leads us to 1796.  If 1666 was the birth of paleontology then 1796 was when it walked.  French naturalist, Georges Cuvier, presented a paper where he compared bones of an Indian and African Elephant, to that of a French mammoth fossil.  The mammoth fossil, he realized, was so remarkably different from its contemporaries that it must be its own species.  What’s more, its species was very likely extinct as nothing like it had been found in the world.  His description of this species and others like the mastodon, the Irish Elk, the giant ground sloth Megatherium were what convinced the scientific community that extinction was a very real, and existentially alarming, idea.

From there, paleontology blossomed into a beautiful flower.  The 1800s was an amazing time for this field.  New fossils were discovered, dinosaurs were named, Darwin’s Theory of Evolution was published, and gradually, the young Earth idea gave way to a much older Earth, one that was millions of years old.  Our modern age gave paleontology incredible advancements such as calculating the Earth’s age through radiometric dating, decoding genetics to understand how traits change and pass to each new generation, how the continents move, and technological access to almost inhospitable fossil-rich lands.  Finally, and most importantly, people from across the world have an intense enthusiasm for paleontology; to find, discover, and learn all we can about our ancient world.  It is truly wonderful and I honestly think we are living at the height of paleontology.

Taphonomic Bias (or the problems of being a fossil)

Soooo…about those shark teeth fossils.  Why did people only find the teeth?  After all, if the shark itself was found then the whole “tongue stones” thing wouldn’t have gotten off the ground.  

Well, sharks are part of a group of fish called Chondrichthyes which includes manta rays and skates.  A common attribute they share is their cartilage skeleton, the same material that our ears and nose are made of.   Cartilage, unfortunately, does not preserve well in the fossil record; it can easily decompose before burial as opposed to the very hard and very durable shark teeth.  Sharks also grow multiple teeth throughout their entire life unlike our twice-and-done chompers.  This creates a strange dichotomy of lots and lots of shark teeth fossils with an extreme rarity of body fossils.

And sharks got lucky!  It’s actually incredibly difficult for an organism to become a fossil.  At least sharks got some hard parts to account for.  There are multitudes of animals like worms, octopi, jellyfish, who are entirely soft, that is they lack concentrated hard minerals in their body.  Their flabby muscle, skin, and tissue can be torn apart by scavengers and rotted away by bacteria or fungi.  The chance for some of these animals to be preserved can be extremely slim.

Even animals with hard parts, like a dinosaur for instance, have absolutely horrible chances to become a fossil.  It’s bad enough that scavengers are eating your body but the forces of nature can erode your bones and scatter them across the land like an overeager toddler and their toys.  Nature’s chaotic handling of organismal leftovers means that if an animal is preserved you’d usually just find about 15% of it.  Many ancient mammals are discovered and identified by just their teeth alone.

(As a side note, do you remember that scene in Jurassic Park where the paleontologists are digging up the Velociraptor?  It’s possibly the most inaccurate thing about the movie!  For one thing, the brushing dust off the dinosaur is laughable as fossils are usually preserved in a hard matrix of rock so you would need drills and chisel tools to remove the surrounding material.  It’s also incredibly rare to have an animal that big with 100% of its bones preserved, connected in a perfect death pose.  Even without scavengers, simple bloating and rotting after death can disarticulate the bones and, at the very least, make them disheveled into a slightly-organized bag-of-bones.) 

Palaeosinopa didelphoides~ | The disarticulated skeleton of… | Flickr
Seen here, a slightly-organized bag-of-bones. Note that this is from a Lagerstatte, Green River Formation, so even these fossil sites have a hard time creating perfect fossils.

Plants face a similar dilemma when they try to fossilize.  On the one hand, whole tree trunks are preserved and can be very common due to their hardy nature and volume.  On the other hand, leaves are easily crushed or eaten by herbivores; flowers bloom briefly in a plant’s lifespan, and seeds love to sprout when buried.  These “weaker” parts are very decisive in identifying plant families and yet are only found in the best of best circumstances.  I commend paleobotanists, scientists who study ancient plants, because they face extreme hurdles in their field to reconstruct ancient plant life.

Then you have the issue that some ecosystems are just not that good at preserving life.  Rivers, lakes, and shallow seas are excellent as they can bury organisms rapidly.  But lifeforms that live far away from water sources or fly have a much lower chance as they are just not commonly exposed to those burial procedures.  They will likely decompose long before a random flood comes and buries them.  Cacti are fantastic examples of this as arid environments aren’t the best for fossilization so the fossils are rare.  Bats are another great example as they are the second most common type of mammal in the world, falling just short of rats, yet their fossil record is incredibly rare.  (as a side note, we’ll be talking about bats later in this series for some really choice fossils!)

Fossil Mammals - Fossil Butte National Monument (U.S. National Park Service)
Seen here; a really choice bat fossil. Image from

Even if you were buried in a good environment it’s not guaranteed that your bones will fossilize.  If the soil is too acidic your bones can dissolve away between 20-100 years.  It’s best to be buried in places that are alkalinic (which is the opposite of acidic), salty, and/or devoid of oxygen; unfortunately, these conditions are not that common.  We’ll go more into these unusual preservations later.

Finally, even IF you were properly buried and you turned to rock and you’re sitting patiently for millions of years…who’s to say paleontologists will find you?  After all you could be buried incredibly far below the surface without anyone suspecting you’re there.  Without any erosion you won’t be exposed at all.  Then again, too much erosion and you yourself will break down from the torrential rains and the nasty winds.  You got to be exposed at just the right time to be found.  So the trillions upon trillions of animals, plants, and so forth that ever lived are winnowed down to a mere sliver of that original count.  There are whole species of organisms that walked, swam, flowered, or spored that we’ll never know lived.  It’s frankly tough being a fossil.

As you can imagine, the Fossil Record is incredibly patchy. I’ve heard many times that figuring it out is like trying to solve a jigsaw puzzle without the box’s lid and a majority of the pieces are missing.  Fortunately, the Fossil Record blesses us with some choice fossil sites that can fill in those gaps and reconstruct our ancient world.

These fossil sites are the focal point of this podcast.  They are undoubtedly the best, most famous fossil sites in the world due to the unusual quality and quantity of fossils preserved in them.  Entire ecosystems can be found at these sites ranging from flowers to ticks, worms to sting rays, and feathers to hair.  These sites are so special that paleontologists call them Fossil-Lagerstätten.

Fossil-Lagerstätten was coined in 1985 by paleontologist Seilacher and his colleagues in their paper titled “Sedimentological, ecological and temporal patterns of fossil Lagerstatten.”  The word “Lagerstätten” is German and comes from a mining term meaning an exceptionally rich seam of minerals, ores or precious metals.  In other words, a bonanza!  And so adding the word “fossil” in front Lagerstätte creates a fossil site of unusually high scientific value.

There are two types of Fossil Lagerstätten, Konzentrat and Konservat.  Konzentrat-Lagerstätten are sites where there is an extremely high quantity of fossils (you can remember this as konzentrat is German for concentrate).  These include places like bone beds and natural animal traps.  The quality of the fossils might not exceptional but the sheer number of specimens can allow us to reconstruct ecosystems and understand the life cycles of a species from infant to adult hood.  A stellar example of this is La Brea Tar Pits, the iconic fossil site in L.A. Paleontologists have found millions of fossils like short-face bears, mammoths, hawks, woodpeckers, and even plants like raspberries and junipers.  The museum even has an absolutely beautiful and breath taking display of 400 almost perfectly preserved dire wolf skulls.  It’s absolutely incredible.

NO SPOILERS] Display wall of Dire Wolf skulls recovered from the La Brea  Tar Pits in Los Angeles. Photo taken at the on-site museum. : gameofthrones
Image taken at La Brea Tar Pits and Museum.

Meanwhile, Konservat-Lagerstätten are fossil sites where the preservation quality of the fossil is incredibly high (again, the German word translates to the similar-sounding word “conserve”).  Sometimes, the place of burial was devoid of oxygen or really salty so scavengers and decomposers couldn’t access the body.  The body would thus lay untouched for millions of years.  Leaves are left uncrumbled, hairs and feathers are still connected to the body, and skin deteriorates to a carbon film leaving a perfect outline of the original body.  One particularly exciting example comes from Florissant Fossil Beds National Monument in Colorado.  Butterflies are found with their legs and antennae; their open wings strike a beautiful pose revealing the patterns that still emboldened them.  Flowers are caught in their moment of bloom and leaves retain their individual veins.  Outside of the rock layers and adorning the landscape are huge stumps of petrified redwoods, a bygone relic of a world that was much warmer and wetter than it is today.

Image from

Now, most Lagerstätten aren’t strictly set in either of these two groups.  Many times, they will lie somewhere in-between them.  Take for instance worms or any other soft-bodied animal.  Modern soft-bodied animals can make up to 60% of animals in a marine habitat.  That’s pretty substantial and this figure was undoubtedly much higher in Earth’s history before the evolution of hard body parts.  As such, if you have a Lagerstätte that was very careful in protecting those animals then this typical Konservat will have strong flavors of Konzentrat as you will have a whole bunch of soft-bodied fossils at once!   A fantastic example of this is the Queen of Lagerstätten, the Burgess Shale in Canada.  Hundreds of thousands of fossils are found here and about 98% of them are soft-bodied.  This is absolutely incredible and the knowledge we gained from it is staggering.


As for me being here, I’ve been affected by Fossil-Lagerstätten in one form or the other since I was young.  I originally developed an interest in dinosaurs when I was a kid but that interest grew and developed into a full on appreciation of all things fossil-related.  I even remember as a kid visiting Dinosaur National Monument and seeing the beautiful wall-to-wall display of fossils in its magnificent Quarry Exhibit Hall.  When I was in college, I got my dual degrees in geology and it was there that I first heard about the concept of Fossil-Lagerstätten, through paleontologist Dr. Paul Selden; who not only taught a course on this fossil sites but also co-wrote two books about them Fossil Ecosystems of North America and Evolution of Fossil Ecosystems.  Both of these books were influential in the making of this podcast.

But Lagerstätten has had a direct influence on my career.  I studied mosasaurs for my thesis and Kansas, my home state, has a bunch of them thanks to the Niobrara Chalk which preserved a whole ocean in stone.  I later became an interpretive park ranger at Fossil Butte National Monument which protects a rich, sub-tropical lake in the desert of Wyoming.  And now I work as a museum educator at the Natural History Museum of Utah which has an amazing exhibit on the Cleveland-Lloyd Quarry; a fossil site with jumbled up bones of Jurassic dinosaurs like Allosaurus.  In general, I just love these sites and I just find them so interesting that I wanted to make a podcast of them where I research and gush all about them!
We will be looking at Fossil-Lagerstätten from across the world that have defied the odds and preserved the best fossils around.  Each episode will focus on a particular Lagerstätte and we’ll talk about what is preserved there, how it got preserved, and why it’s so special.  We’ll touch on the lives of scientists who were influential in their discovery and successes.  We’ll even learn about other paleontological knowledge and how it relates to the sites like the fossilization process and the Earth’s many time periods.  I hope you’ll enjoy this season and please leave a review on my website or on iTunes and let me know how I’m doing!  I appreciate any feedback.  See you next time!

Season 1

Fossil Bonanza Premieres Today!

Happy National Fossil Day everyone! Well, after 10 months or so it finally happened. I’m proud to announce that my Fossil-Lagerstatten podcast, “Fossil Bonanza,” finally comes out today. Although it hasn’t shown up on Google Podcasts yet, you can get it at Spotify here:
And iTunes here:

Anyway, I’ve updated the home page so it will have the RSS feed of my podcast. I think I’ll also update the website’s layout to make it more user friendly so you might see some changes there. Also! I’ll be posting later the transcripts of Episode 1 and 2 today so if nothing else, at least you can read the episodes.

Thanks everyone for reading and I hope you enjoy the podcast! I put a lot of hard work and love into it and I’m proud with the end result.

Until next time!

Season 1

Fossil Bonanza will Premiere on October 14th

Hey everyone! Excited news. I’ll be premiering my upcoming podcast, “Fossil Bonanza,” on October 14th, National Fossil Day! It’s been a long time coming and after working months of researching, writing, recording, and editing, I’ll finally premiere the podcast. I’m very, very excited! I’m very satisfied with the end result.

Fossil Bonanza Logo

So far, barring any major surprises, this is what the schedule will look like:
October 14th: Episode 1-Introduction and Episode 2-Beecher’s Trilobite Bed
October 28th: Episode 3-Posidonia Shale
November 11th: Episode 4-Amber Introduction
November 25th: Episode 5-Dominican Amber
December 9th: Episode 6-Jehol Biota Part 1
December 23rd: Episode 7-Jehol Biota Part 2
January 6th: Episode 8-Naracoorte Caves

The first five episodes are already finished and the last three just need to be recorded and edited. Depending on how well Season 1 does I will work on Season 2 but that will take awhile. Thankfully, since I have experience with this and know how to produce these I somewhat expect the process to be a little faster? But we’ll see.

I’ll post a link to the feed on my website and I’ll post rough transcripts of the episodes the day they premiere. Looking forward to it!

Season 1

Season 1 Update

Hello everyone! It’s been a long time coming but I’m finally seeing the light at the end of the tunnel. After months of research and writing I’m finally recording and editing season 1 of Fossil Bonanza! I can’t tell you how happy I am that this massive project will finally be released. Bar any kind of major surprises Season 1 will be as follows

Episode 1: Paleontology and Lagerstatte Introduction
Episode 2: Beecher’s Trilobite Bed
Episode 3: Posidonia Shale
Episode 4: Amber Introduction
Episode 5: Dominican Amber
Episode 6: Jehol Biota Part 1
Episode 7: Jehol Biota Part 2
Episode 8: Naracoorte Caves

I wanted to choose five amazing fossil sites that come from different time periods, geographic locations, organisms preserved, and method of preservation. I feel that these five really encompasses the diversity that Lagerstatten can achieve.

No hard plans on a release date yet but these episode will be released every two weeks with episode 1 and 2 released simultaneously.

Also, looking for guest experts to talk about Lagerstatten particularly if it relates to the five I’m focusing on. So if you have studied these fossils and are willing to spend some time with me, send me a message!

That’s all for now!