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Throughout our planet’s history, billions
of species have gone extinct.
In fact, over 99% of the species
that have ever existed, don’t anymore.
Some of them disappeared long ago, leaving
behind the occasional fossil to study.
Others went the way of the dodo and were killed
off either directly or indirectly by humans.
But every once in a while, a creature we thought
had kicked the bucket is found … still kicking.
Here are seven animals that turned out to
not be extinct after all.
One of the most well-known
examples of this phenomenon
is the coelacanth, a kind of simple fish.
Until the 1930s, we’d only seen it in fossils,
and the fossil record suggested it died off
not long before the non-avian dinosaurs did,
over 65 million years ago.
But then, in 1938, a museum curator named
Marjorie Courtenay-Latimer discovered a live
specimen someone had fished off the coast
of South Africa.
These days, we know of two different living
species of coelacanth, one in the western
Indian Ocean, and the other in waters near
Indonesia.
They’ve been so hard to find because they
tend to live between about 150-250 meters
down, in the ocean’s twilight zone.
Which, despite the name, is not a dimension
not only of sight and sound, but of mind.
It’s just pretty dim down there.
On top of that, coelacanths also gather in
caves during the day,
only to leave at night to feed.
But now that we’ve found them, we’ve learned
that they’re kind of awesome.
The coelacanths we’ve found are nearly identical
to fossils hundreds of millions of years old,
so they have a lot of anatomical features
we’ve never found in modern animals.
For example, they have a hinge inside their
skull that’s unique among all living vertebrates.
It allows the back of their skulls
to swing upwards,
so they can basically
open their mouths super wide.
So basically they’s be perfect dental patients,
if they weren’t fish.
I mean, I don’t know….
Maybe they have tooth problems.
Coelacanths are also the only living fish
to have seven lobed fins — and we only know
of one other living fish with lobed fins at
all, the lungfish.
Four of the coelacanth’s fins are paired
up, and they move similarly to how land-based
animals might move their legs.
Because of this, scientists used to think
that the coelacanth could be the so-called
“missing link” between sea and land animals,
but genetic sequencing has debunked that.
The role most likely goes to the lungfish,
which is the coelacanth’s closest relative.
But don’t worry, coelacanths.
We still think you’re special.
Like the coelacanth, we used to think the
Kha-nyou, or Laotian Rock Rat, was long gone.
But instead of being found by fishermen, this
animal was spotted at a meat market.
In the late 1990s, two scientists visiting
Laotian meat markets independently identified
what appeared to be a new species of rodent.
The animal, which looked like an adorable
cross between a squirrel and a large rat,
was a regular on the market menu,
but it took nearly a decade
to confirm what it really was.
In fact, the first photographs of a living
Laotian Rock Rat weren’t captured until 2006.
Based on initial DNA testing, scientists first
thought the creature was part of a brand new
taxonomic family, one most closely related
to guinea pigs, African mole rats, and porcupines.
But within a year, new analyses revealed that
it was actually the only living species from
its taxonomic family Diatomyidae,
which disappeared
from the fossil record
around 11 million years ago.
Today, the rodent is mostly
found in Central Laos,
but a smaller population has
also been found in Vietnam.
Both groups live in the crevices of limestone
towers in forests.
So, that might explain why they’re hard
to find.
Since they’re so rare, most of what we know
about the species comes from analyzing bushmeat
samples and talking to the locals who hunt
them.
But the scientists are pretty convinced that
the rodents are nocturnal and mostly herbivores,
although they might occasionally eat insects.
If you’re looking for an animal we thought
was extinct for a really long time,
you might want to try monoplacophorans,
a type of mollusk
that we thought disappeared
around 400 million years ago.
And then in 1952, ten live specimens were
collected from the seafloor near Costa Rica,
over 3500 meters below the surface.
After that, researchers realized
that monoplacophorans
had actually been found before,
as early as 1869!
But they were all incorrectly identified as limpets,
a kind of snail, because of their similar shape.
Today, we’ve found around 30 distinct species,
and all of them fall into the subcategory Tryblidia.
As the name suggests, monoplacophorans have
a cap-like shell with just one plate.
In fact, their shell microstructure and musculature
are basically identical to those found in
fossils half a billion years old.
But a lot about them, including how they grow
and reproduce, and their relationship to other
mollusks, is still a big mystery.
They’re so simple that researchers once
believed they could be the original mollusk,
from which all others descended.
And because they show signs of segmented organs,
they were also seen as a potential missing
link between all mollusks and annelids, or
segmented worms.
They probably aren’t either of those things,
though.
Newer research suggests that, instead of being
the OG mollusk, they’re actually a super
specialized branch on the mollusk family tree
… which is only getting more complicated
as we learn more about it.
Mollusks might be simple, but they’re not
the simplest animal on our list.
That honor goes to the Neptune’s Cup Sponge,
which was first discovered around 1820 off
the coast of Singapore… and was very quickly
harvested to extinction.
Or so we thought.
These sponges could grow to over a meter tall
and wide, and their cup-like shape was so
convenient that people actually used them
as bathtubs for their babies.
Because they were so large, they were a valuable
collectors item for individuals and museums,
and we kept harvesting them until they were
almost all gone.
The last time anyone recorded a living one
was 1907, at least until 2011, when scientists
discovered two living specimens in the waters
off Singapore’s St. John’s Island.
Before then, in the 1990s, we’d seen dead
sponges wash up onshore in Australia, so there
was some evidence they
weren’t extinct after all.
But it took over a decade to find these live
ones.
The two sponges were young, only about 30
centimeters in diameter, which is nowhere
near as large as they could grow to be.
But they did teach us that these sponges don’t
grow as slowly as we used to think.
The two young sponges grew several centimeters
over just a few months, which is a lot compared
to other species of sponge, which only grow
that much in a year!
As of this May, three more live sponges have
been discovered, and to help conserve the
species, they’ve been transplanted so that
they’re close enough to each other that
they can reproduce.
It’s safe to say we will not be using them
for baby baths any time soon.
Or ever.
Let’s not make that mistake again.
The first fossils of the Mallorcan Midwife
Toad were found in 1977, on the island of
Mallorca in the Mediterranean.
Based on those fossils, researchers thought
it had been extinct for a few thousand years,
probably because Romans had introduced predatory
snakes to the island.
But only three years later, we found live
ones!
Midwife toads are not especially talented
at helping others through labor or anything.
The name comes from how the males care for
fertilized eggs: they carry a string of 7-12
of them wrapped around their hind legs until
they hatch.
Like a little tadpole fanny pack!
These tiny toads only grow to be 4 centimeters
long, and they used to be found all over Mallorca.
But invasive species have pushed them into
the northern mountains, where they live in
small streams carved into limestone.
Thankfully, active breeding programs across
Europe have existed since the mid-1980s, and
the first toads bred in captivity were reintroduced
to the island in 1989.
So far, these conservation efforts have been
considered successful, and the toads were
even reclassified in 2004, from Critically
Endangered to Vulnerable.
So things are looking up!
Meanwhile, just east of Australia, you’ll
find the 10 kilometer-long Lord Howe Island,
formerly the home of the creatively named
Lord Howe Island Stick Insect.
It’s also nicknamed the Land Lobster or
Tree Lobster, depending on who you ask.
They are not as big as actual lobsters, but
they can grow to be 15 centimeters long, or
about as big as your hand, which, if you ask me,
is bigger than any insect really needs to be.
Either way, we thought they’d been wiped
out not long after 1918, when a shipwreck
on the tiny island introduced a bunch of black
rats that would’ve considered stick insects
a really tasty snack.
But it turns out that about 25 kilometers
away, on an even smaller volcanic outcrop
called Ball’s Pyramid, a very tiny population
survived.
And we finally found them in 2001!
Unfortunately, Ball’s Pyramid isn’t an
ideal environment for them.
These insects used to live in forests in the
hollows of tree trunks, but there aren’t
any forests on the outcrop.
Instead, they hide in holes full of plant
debris.
And they can only feed on one plant that grows
there: the tea tree.
Which can really be a problematic eating strategy,
as pandas have found out the hard way.
In 2003, two insects were brought to the Melbourne
Zoo to begin a breeding program, and so far,
over 14,000 insects have been born there.
This year, a new female named Vanessa was
brought from Ball’s Pyramid to the zoo for
some much-needed extra genetic diversity,
and she’s definitely living her best life.
She currently has her own $80,000 climate-controlled
glass house.
But 14,000 insects does not mean the species
is saved.
With fewer than 30 of them in the wild, the
Lord Howe Island Stick Insect is a strong
candidate for the world’s rarest insect.
And even though Ball’s Pyramid is nearly
inhospitable for them, it’s not safe to
start reintroducing these critters to Lord
Howe Island until conservationists take care
of the rat problem, because there are still
plenty of those guys running around.
So only time will tell if they’ll ever be
able to return home.
Finally, for our last not-dead-yet animal,
we have the Ecuadorian Horned Anole,
or “the Pinocchio lizard.”
One look at a male specimen
and you will see why.
The anoles were first discovered in the 1950s,
but the few scientists could find were all
male, so they couldn’t tell if the females
also supported that impressive nose.
And within a decade, all signs of them had
vanished.
Their suspected extinction was probably caused
by deforestation, since the anoles were only
found within about 250 square kilometers of
forest near the village of Mindo.
But in 2005, a group of birdwatchers traveling
through the area saw a single, strange lizard
crawling along a road.
They caught it and snapped some photos,
and it was identified as the
long-lost Ecuadorian Horned Anole.
Several years later, scientists captured specimens
for study.
They had to go at night because these anoles
are super well camouflaged during the day,
and they like to hang out high up in trees
and creep around very slowly.
But at night, they change color and become
pale enough that flashlights can pick them
out amongst the foliage.
So far, we don’t know why they do this,
but it is convenient at least.
Even though we know they’re alive now, researchers
still don’t know much about these lizards.
They can actually wiggle their proboscis,
but scientists don’t know
exactly how they do it.
They might have muscles in their snouts, which
would make them different from other lizards.
Or maybe their bodies pump fluid into and
out of them.
If nothing else, researchers are pretty confident
that the proboscis is used for mating displays,
as opposed to, like, fighting other males.
That’s partly because they’re super flimsy
and would make for terrible nose swords,
but also because of directly
observing males flourishing them
around before getting it on with their partners.
We, of course, don’t know exactly how many
Ecuadorian Horned Anoles there are, but so
few of them have been spotted that they are
listed as an endangered species.
Hopefully we can keep them and their habitat
around long enough to get some answers.
No matter what the pressures on these organisms
that have pushed them so far out of our grasp
that we just thought that they were gone,
it’s always an exciting moment for science
when a species seems to
come back from the dead.
Some of them act like little time capsules
from Earth’s past, and all of them help
us better understand the family tree of life.
And hopefully, we will be able to keep them
alive and well for years to come.
Thanks for watching this episode of SciShow!
If you love learning about what life used
to be like on Earth, including about some
animals that did go extinct, you can check
out new sister show Eons over at youtube.com/eons.
It’s so good!
I’m loving doing it!
The scripts are so-
Thank you to all the writing staff there.
It’s been such a wonderful journey into the
marvelous and humongous
history of life on Earth!
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