Here are animals that have been hanging around for millions of years!
7 - Horseshoe crab
Horseshoe crabs are ancient-looking creatures with hard shells on their backs.
They almost look like they don't belong in our time period, as if they somehow skipped
evolving along with the rest of the species on our planet.
However, it's not that they didn't evolve.
Rather, it was really that there wasn't any outward pressure from a competitor causing
them to leap forward, so they evolved at a slower rate.
Hey, if it ain't broke, don't fix it right?
Ehh, I'm always for improvement but that's just me.
Anyways, fossils of horseshoe crab ancestors can be found dating as far back as 500 million
years, but they're recognizably different from the horseshoe crabs that can be found
today.
On the other hand, fossils from roughly 150 million years ago look extremely similar to
modern day horseshoe crabs.
This means that for the last 150 million years, horseshoe crabs have found a comfortable niche
to fill in the animal kingdom.
Hey, they can't complain about that nice little run.
Fun fact, these days we actually harvest horseshoe crab blood for medical purposes.
The blood of a horseshoe crab is blue, because of its use of hemocyanin to carry oxygen instead
of hemoglobin, the stuff that makes our blood red.
6 - Duck-billed Platypus
The duck-billed platypus looks basically like a real-life cartoon, with a duck-like bill
for a mouth, an otter-like body, and a beaver-like tail.
Coming in at nearly 2 feet long, these mammals hunt small prey very effectively underwater,
by scraping up insects, larvae, shellfish, and worms from the seabed.
The platypus is a nearly unique mammal, in that only itsef, and the spiny anteater, lay
eggs to reproduce.
Not only that, the platypus is also one of very few mammals that produce venom!
Male platypus have spurs on their heels that secrete venom.
Their glands only produce venom during mating season, leading many scientists to believe
that it's primarily for competition between males, rather than protection from its predators.
In the event that you're unlucky enough to get into a fight with a male platypus while
it's trying to mate, here are some things you should know about the venom.
It's not lethal to humans, but it causes intense pain almost immediately.
If you ever get stung, there will be swelling, and following the swelling, the area will
develop hyperalgesia for up to a few months, meaning that it'll be more sensitive to
other sources of pain.
Yeah, just a few months?
I'm good on that.
While it seems that the platypus can only be described as strange, but how DID they
exactly end up this way?
Approximately 160 million years ago, mammals were still evolving from reptiles.
Platypus are a member of a group of animals called monotremes, one of the earliest offshoots
of the mammalian family.
Because of its early divergence from the other mammals, it still retains many traits similar
to reptiles and birds, such as laying eggs, and having a beak.
Monotremes are a great example of the randomness of evolution.
If a certain trait helps an animal to stay alive, obviously it'll pass on its traits.
Somehow, all these strange parts of the platypus combined to form an animal that was successful
enough to survive for hundreds of millions of years.
5 – Crocodiles
Crocodiles are truly terrifying animals, as they have jaws capable of delivering a bite
of up to 3700 pounds per square inch of bite force.
They hunt efficiently by hiding until prey comes in range, then lunging faster than you
could blink.
Once they have a hold of their prey, there's pretty much no chance of escape, as crocodiles
are able to hold on with the strongest bite force of any animal on the planet.
Once they have their prey in their jaws, they then pull their prey underwater to drown it.
While the crocodiles you know of today have remained relatively unchanged for millions
of years, their ancestors have actually been around a lot longer than that.
Crocodiles share a common ancestor with their cousin dinosaurs.
Crocodiles evolved into what they are today over 65 million years ago.
The Archosaur was the ruling land lizard of the time, and it evolved into both dinosaurs
and crocodiles around 200-300 million years ago.
Believe it or not, members of the crocodylian family were often fairly small at that time.
Many of them were quick, agile land creatures, sometimes even running on just two legs.
Some of them were even vegetarians!
Around 200 million years ago, crocodiles went for a swim, likely as a result of the dinosaurs
becoming the new lord of the land, and the water is where they stayed to evolve.
The new habitat for crocs helped them to develop the features they have today: long bodies
with powerful jaws.
Around 100 million years ago they actually started getting bigger.
It was around this time, in the Cretaceous period, that the largest crocodile in history
lived.
This monstrous croc was called the Sarcosuchus, or, as National Geographic likes to call it,
the "SuperCroc".
Since the Sarcosuchus continued to grow for its whole life, this ancient croc could reach
lengths of up to 40 feet, which is nearly double the length of the largest known modern
crocodile, the Saltwater Crocodile!
YO!!!
If I ever saw a 40 foot crocodile in real life, I'd seriously consider switching continents!!
Luckily for us and a lot of small animals out there, the descendents of this massive
croc went extinct, and a slightly smaller crocodile, the Deinosuchus, evolved into what
we have today.
4 - Coelacanth
The Coelacanth is a fish that was thought to have gone extinct approximately 65 million
years ago, during the extinction event that took down the dinosaurs.
This fish was known only from fossil records until back in 1938, when one of these guys
was found living in the Western Indian Ocean!
So how old exactly is the Coelacanth species?
Well, scientists have found fossils from as far back as roughly 360 million years ago,
making it even older than the crocs, though it's not the oldest animal species on this
list.
The coelacanth was long considered a "living fossil" because it was believed to be the
sole remaining member of a taxon otherwise known only from fossils, with no close relations
alive.
However, several recent studies have shown that coelacanth body shapes are much more
diverse than previously thought.
According to genetic analysis of current species, the divergence of coelacanths, lungfish, and
tetrapods is thought to have occurred about 390 million years ago.
Some scientists believe that the Coelacanth is actually one of the missing links in the
evolution from fish to four-legged terrestrial animals, but there's a bit of controversy
and dissent around this topic.
There are other scientists claiming that it's actually just a close relative to the ancestor
of tetrapods.
I bet dinner conversations and happy hours with these research scientists are just scintillating
phew.
Anyways, unfortunately, although the Coelacanth isn't extinct, it IS critically endangered.
There are only two known species of Coelacanth, making it an extremely rare fish, and one
that may be gone not too long from now.
But hey even with all the disagreements with what exactly happened with this fish, much
props to them for swimming around for this long!
3 - Nautilus
Fossils of early ancestors of the Nautilus have been found as far back as 550 million
years ago, close to the very beginning of complex animal life.
Between 505 and 408 million years ago, giant Nautiluses with straight shells dominated
the ocean, since they were larger and more capable of swimming than the other residents
of the sea.
Their shells protected their bodies from predators, while also providing chambers that could be
filled with gas, giving them a natural buoyancy.
Although only a few members of this family remain today, the species was once extremely
diverse.
Somewhere in the last 500 million years, these Cephalopods diverged into multiple species,
such as Squid and Octopi, making these species very distant relatives of the Nautilus.
However, the modern Nautilus family can be traced back to the late Triassic, roughly
215 million years ago.
As most species have done in the last few millions of years, Nautiluses have become
smaller, now measuring a little less than one foot in diameter at most.
Their shells are curved, and are one of the best examples of a logarithmic spiral that
can be found in nature today.
Okay, I'm not really that big a science nerd, but even I gotta admit, that's pretty
cool!
Nautiluses typically scavenge for food, and they're capable of living in lower oxygen
conditions.
This resilience may explain how they survived the extinction events at the end of the Cretaceous.
You may be wondering why the Nautilus looks so familiar.
If you're a Pokemon fan, you've probably seen the ancient fossil pokemon, Omanyte.
Omanyte looks very similar to the Nautilus, and even its gender ratio in the game is similar
to what we know about Nautiluses in real life, with about 85% of them being male.
Why do I know that?
Uh, it's because of something called GOOGLE, and NOT because I'm spending hours each
day dedicated to catching pokemon or anything pffffft.
Ahem…..unfortunately, Nautiluses live a few hundred meters below the surface of the
ocean, so we probably won't be exactly catching one any time soon in real life.
2 - Goblin Shark
Sometimes called a "living fossil" because of its primitive features, the goblin shark
is the only known representative of the Mitsukurinidae family.
As a species, the goblin shark appears to be unchanged for the last 40 million years,
but scientists noticed many similarities between the goblin shark and Scaponorhynchus, an extinct
Mesozoic shark.
The goblin shark has a long snout, shaped like the blade of a sword, and a thin body
covered with dermal denticles, which are small, tooth-like projections.
It has a slightly pink colour, because of its blood vessels being so close to its skin,
and it has a few small fins.
Many of these features lead scientists to believe that it's a slow moving shark.
Luckily for the goblin shark, it's still capable of hunting in its own way.
It can detect slight electrical fields that are produced by nearby prey, with its long
snout that's covered with ampullae of Lorenzini, which are special sensing electroreceptors
that's basically a network of jelly-filled pores.
Combine its nose and its limited sight, the goblin shark can hunt for fish, cephalopods,
and crustaceans both near the sea floor and in the middle of the water column.
The Goblin shark moves slowly enough towards its prey to avoid alarming it, and then it
snatches it up with a quick motion of its mouth.
To make things easier for itself, its jaws can extend, allowing it to catch prey before
they can react.
This shark is about one and a half times the size of an average man, and it lives and hunts
on upper continental slopes, roughly 270-1000 meters below the water surface.
Small numbers of goblin sharks are unintentionally caught by deepwater fisheries, but the International
Union for Conservation of Nature has assessed goblin sharks as Least Concern despite its
rarity, because of its wide distribution and low incidence of capture.
1 - Jellyfish
You may have seen a jellyfish before if you've been to the ocean, but in the most likely
case, you probably haven't seen jellyfish most of the time they're around as they're
actually pretty difficult to see.
Jellyfish are overpopulated in a lot of areas, and sometimes venomous to touch, leading us
to classify jellyfish as a nuisance.
Here's a newsflash, some species of jellyfish are deadly even to humans, just in case you
didn't know.
In recent years, certain industries have lowered the populations of some natural predators
of jellyfish, leading to the huge overpopulation of jellyfish.
Basically, humans are making it a lot easier for jellyfish to grow in number, and it's
having a real impact on the ecosystems of the ocean.
Massive amounts of jellyfish means that massive amounts of plankton are eaten, so much so
that it's affecting other species that also rely on plankton as a source of food.
It really goes without saying that jellyfish pose a threat to human activities too.
Some beaches are so overpopulated with jellyfish that you can't go swimming without wading
through a whole pack of them.
Since their stings range from painful to deadly, it basically just totally sucks getting stung.
But, while the number of jellyfish in recent years has been growing, they've been around
stinging things for a lonnnnng long time.
Jellyfish are ancient animals, dating as far back as 500 million years!!
Some scientists believe that they were one of the first complex life forms, though there's
no consensus on that yet.
For the last 500 million years, jellyfish have done pretty much nothing to evolve except
survive.
They have the most basic nervous system known to man, and don't do much except eat, reproduce,
and annoy people.
They have no brain, so they just float around, automatically responding to any stimuli around
them.
They orient themselves based on light sources, and they sense heat, and various other things
around them in order to survive and eat.
So far it seems that even their lack of intelligence can't keep their numbers down.
Hey, is it just me or do jellyfish remind you of certain groups of people?!
Seriously, how did the word jellyfish not ever become an insult?!
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