This episode is supported by Squarespace If horror movies have taught us anything,
it’s that the dead have this knack for coming back from the grave and showing up again to
freak us out. And in a way, the same can be said for some fossil
animals. Natural history is full of things that
were long thought to have gone extinct only to show up again, alive and well. Paleontologists have a word for these kinds
of organisms: They call them Lazarus taxa. These taxa get the reputation for being well,
dead because their remains suddenly disappear from the fossil record, making it look like
they’ve vanished, even though they’ve stayed around, often for millions of years. But, aside from blowing our minds by re-appearing
when we least expect it, Lazarus taxa give us a fascinating lesson in the limits of what
the fossil record can really tell us. One of the most famous stories of life returning
from the depths of time starts over half a billion years ago, in the Cambrian Period,
right when life was getting its feet under it. Literally. Even though life originated on Earth about
3.8 billion years ago, for most of Earth’s history, the story of Life was a story of
single cells. Multi-cellular life didn’t show up until
about 900 million years ago, and the first squishy things we can call the earliest animals
only appeared about 100 million years after that. So, animals are still the new kids on the
block. But by 508 million years ago, during the height
of the Cambrian, the Animal kingdom was running riot. And there’s no better place to see the evidence
of this, than in the gray stone of British Columbia’s Burgess Shale. Discovered by paleontologist Charles Walcott
in 1909, the Burgess Shale is a fossil wonderland brimming with creatures so amazing, and so
confusing, that for decades scientists couldn’t figure out even the most basic information
about them -- like which part of the animal was the top, and which was the bottom. But over the past century, experts have sorted
through all the armored body segments, appendages, crazy spikes, and other fossil features, to
reveal a menagerie unlike any that had existed before. Just look at Anomalocaris. This meter-long predator was only a threat
to worms on the seafloor, but with 11 pairs of fins, grasping appendages, and a mouth
like a camera aperture, it looked menacing enough to star in its own horror movie franchise. Then there’s Hallucigenia, cousin of today’s
velvet worms. When it was first described in 1977, experts
thought it tip-toed around the seafloor on long spikes. Only later did it turn out that they were
looking at it upside down! There were also creatures like Ottoia, a segmented
worm with an extendable mouth for slurping up small prey. And the elegant, lacy arthropod Marrella. And then there’s Herpetogaster, which …I'm not going to describe using my words We even had our own little cousin twitching
around in those days -- a little, worm-like swimmer that scientists know as Pikaia. Simple as it was, this was one of the earliest
chordates -- part of the family that would give rise to the vertebrates and includes
us, making us cousins over 500 million years removed. The major groups of animals we see around
us today -- from sponges to arthropods to chordates -- all showed up in this little
window of time in the Cambrian. But then something happened. Or at least, appeared to happen. At the end of the Cambrian, many of these
strange creatures just … vanished. The period right after the Cambrian is the
Ordovician, and this is when paleontologists saw a major change in the composition of animal
life. Many of the weird animals found in the Burgess
Shale - like Anomalocaris - were suddenly gone. Exactly what caused this apparent extinction,
no one knew. Looking at the rocks simply turned up very
different communities of animals from one time period to the next. This is how extinction events turn up in the
fossil record - sharp breaks in the continuity of life. But then, a chance discovery changed
everything, effectively erasing what experts thought was the Cambrian Extinction. While looking for fossils in Morocco’s Draa
Valley back in the 1990s, local fossil hunter Ben Moula stumbled across a cache of strange
invertebrates. He showed the spot to a PhD student working
in the area who recognized the ancient life in the rocks. What they found were perfect examples of Lazarus
taxa. The fossils they found were about 488 million
years old -- which put them in the Ordovician. But some of the creatures looked all wrong
for their age. Many of them more closely resembled animals
from the Burgess Shale, which lived 20 million years earlier. Some of the fossils were the spitting image
of Marrella. And one of the most impressive finds was a
two-meter-long cousin of Anomalocaris with its same, frond-like appendages. It turned out, Cambrian creatures that scientists
thought were extinct had survived for longer than anyone ever knew -- for tens of
millions of years! And this this is by no means the only time
that Lazarus taxa have been discovered. The big, primitive-looking fish known as the
coelacanth was thought to have been extinct for 66 million years, until one was hauled
up off the coast of South Africa in the 1930s. Likewise, the redwood tree known as the Metasequoia
was known only from fossils, before a botanist found living specimens in China in the 1940s. But, why does this happen? How can a living thing disappear from the
fossil record, and then show up later, alive and well? Well, Lazarus taxa can come about for lots
of different reasons. Take the coelacanth. It lives in the deep sea, in environments
where living things don’t easily fossilize. It takes special conditions for fossilization
to happen, and, for whatever reason, the places that coelacanths like just don’t preserve
fossils very well. That’s why there was such a long gap in
their record. They didn’t live in the right places to
leave their bones behind for us to find! Something similar happened with all those
Cambrian creatures that paleontologists thought were long gone. Although some had hard exoskeletons, almost
all of them were soft-bodied. And they need very, very special circumstances
to become fossils. Unless they’re buried really quickly by
a lot of sediment, their bodies are likely to decompose and leaving nothing behind. In fact, there were probably way more living
things on Earth than we’ve found fossils for Of all the species that have ever lived, only a
handful happened to make their homes in places where fossilization was possible. And of that fraction, only a smaller fraction
actually did fossilize and were preserved in rock that happened to be close enough to the surface. And of that even tinier fraction, only a relatively
small number are in places that scientists have actually been to. So, the story that the fossil record tells
us isn’t like a movie, with every frame intact. Instead, the story it tells is choppy and
confusing, with lots of weird plot holes, missing scenes, and characters that seem to
be written out of the script for no reason. It’s crazier than Twin Peaks. Which I can make that reference again because it's relevant...at the moment But finding those Moroccan fossils was like
recovering a lost reel of film. And that’s what led paleontologists to realize
that the Cambrian extinction never happened. It turns out that the kinds of animals that
thrived in the time of the Burgess Shale hadn’t died out. They just didn’t fossilize well. And this created a false gap in the fossil
record, while they still swarmed the seas. Of course, those Cambrian animals did go extinct
eventually. But what makes them special is that they managed
to persist for longer than paleontologists ever expected. And this highlights a fundamental truth about
the past. The fossil record is huge, spanning more time
than we -- who live on the order of decades -- can fully understand. And we’ve only started to explore all of
the places on Earth where fossils might be found, and learn what they can tell us. If what we’ve learned so far is any indication,
the past is still full of surprises! So if the story of life on Earth really were
like a Hollywood film, Lazarus taxa would be less like b-movie zombies that come back
from the dead, and more like action heroes, who manage to survive when everyone has given
up on them. But instead of cheating death, these guys
managed to cheat extinction. Don’t you need a place to post all your
Jurassic Park fan art? Of course you do! Whether you need a domain, a website or online
store, Squarespace can help you make your next move. And Squarespace provides an all-in-one platform
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ever. And since you’re an Eons viewer, you can
start your free trial at squarespace.com/eons and enter offer code “EONS” to get 10%
off your first purchase. So what do you want to know about the story of
life on Earth? Let us know in the comments. And don’t forget to go to youtube.com/eons
and subscribe! Now do yourself a favor and check out some
of our sister channels from PBS Digital Studios. Your brain will thank you!
I'm a simple hairless chimp, I see eons I upvote.
The server doesn't preserve every corpse every time someone gets nerfed. Can you imagine how many there'd be if it did??
Fossilisation is like an Easter Egg for players who (usually accidentally) manage to not get found and mined for XP by the scavenger guilds and bacteria when they die. It's relatively useless for actual gameplay for almost everyone though.
The only builds who seem to care about it are the human players who specialised in the palaeontology skillset, which is an extremely niche knowledge (arcana) skillset playable only for the human build. It's interesting for learning about the history of the game but that's about all you can do with it - I mean there's not much need in-game to know a lot of detail about builds that got nerfed in earlier patches, other than just general interest. Those players seem to be among the rare few who care more about the lore than the actual gameplay, since it takes so much grinding to spec in to that skillset anyway even though the game doesn't reward you much for it. Their playthroughs are how TierZoo gathers a lot of its info about earlier patches though, so us casuals should definitely be grateful.
This means that some dinos could possibly still be playable