15). Estemmenosuchus
They don’t make animals like this anymore. Estemmenosuchus is one of
the most bizarre-looking prehistoric monsters; it belonged to the group
of the dinocephalians, and despite their dinosaur-like appearance, they
were actually more closely related to mammals… including us!
Estemmenosuchus was the size of a rhinoceros, and it too had a horn on
its nose, but it also had antler-like horns on the top of its head, and
strange, bony protrusions coming out of its cheeks; no one knows what
they were used for. It also had a set of monstrous, sharp teeth, but
scientists aren’t sure about its food preferences. Personally, I believe
this thing was big and scary enough to eat anything it wanted. Fossil
remains of Estemmenosuchus have been found in Russia; it lived in the
Permian period, long before the appearance of dinosaurs.
14). Acrophyseter
This was an ancient relative of today’s sperm whale, which as we all
know (or should know) is huge, eats lots of squid and has never been
known to attack humans without provocation. Acrophyseter was the
complete opposite; it was moderately sized, and didn’t feed on squid but
rather on other marine mammals and even on sharks! Its horrible-looking
teeth were deadly weapons and have given Acrophyseter and its ancient
relatives the nickname of “killer sperm whales”. Acrophyseter’s fossil
remains have been found in Peru; it lived in the Miocene period, which
seems to have been the best epoch for scary marine monsters including
giant dolphins, colossal sharks and even monster penguins and seals.
13). Gigantopithecus.
It’s name says it all; it was a monstrous ape, closely related to the
orangutan, that roamed the bamboo forests, jungles and mountains of
China, India and Vietnam during the Pleistocene. It was a vegetarian,
but scary nonetheless; it could grow up to three meters tall and weigh
up to 550 kgs! Its strength must have been extraordinary and probably
kept it safe from most predators. It finally went extinct 300.000 years
ago, possibly due to overhunting by early human species or as the result
of climate change. Of course, all yeti and bigfoot believers like to
think that Gigantopithecus survived somehow in the most remote parts of
the Himalaya…
12). Epicyon
Epicyon could well be described as a giant pitbull on steroids. It
was a member of the Canidae or dog family, but whereas modern day canids
are built for speed and endurance, Epicyon was built for brute
strength, and had jaws so powerful that they could crush bone as if they
were crackers! This beast ruled the plains of North America for fifteen
million years, before it was replaced by big cats (including
sabertooths).
11). Edestus
Today’s great white shark probably has some of the most nightmarish
set of teeth in Nature, but its distant prehistoric relative Edestus was
so scary that it would make the great white look almost cute. Edestus
was about seven meters long and was one of the top predators of the
Carboniferous seas. However, scientists still don’t know how it used its
extraordinary teeth; instead of constantly losing the worn out teeth
and replacing them with the new ones growing in rows behind, as modern
day sharks do, Edestus didn’t lose its teeth at all; instead, the new
teeth pushed the old teeth out of the mouth and, eventually, the gums
and teeth would protrude out of the mouth like a pair of monstrous
scissors. Regardless of how it did it, it seems obvious that Edestus
could possibly cut any other creature in two with ease. But we still
have trouble to imagine how a very old Edestus would “function”, or even
how would it look!
10).Gorgonopsid
This creature has earned some popularity recently thanks to the
British sci fi show “Primeval”, where it was the very first monster to
appear. Although real life gorgonopsids where a tad smaller than the TV
version (the largest species, such as Inostrancevia and Leontocephalus,
could grow up to six meters long), they were just as terrifying; as a
matter of fact, they were the dominant predators during the late
Permian, before dinosaurs and their relatives took over. Gorgonopsids
had a set of deadly saber-teeth (some species had two sets of them)
which came handy when hunting some of the largest Permian herbivores,
often the size of rhinos or bigger.
They were quite agile and could probably run quite fast, unlike the
predators that came before them. Despite their reptilian appearance,
gorgonopsids were actually closely related to mammals, and it is even
possible that they were covered in fur!
9). Terror bird
Terror birds, formally known as Phorusrhacids, were the top predators
in South America and parts of North America during the Miocene,
Pliocene and Early Pleistocene periods, before they were replaced by big
cats and other carnivorous mammals. They were unable to fly, but could
run very fast (as fast as a cheetah, according to some scientists!) and
were very large; the largest species could grow up to three meters tall
and weigh up to half a ton. Their main weapon was their head, which
could be up to one meter long, allowing them to swallow prey as large as
a dog in one single gulp! However, thanks to the hooked tip of the
bill, similar to that of eagles and hawks, the terrors birds could kill
and devour prey much larger than a dog, including horses, camels, etc.
8).Madtsoia
Madtsoia would be the worst nightmare of anyone with a phobia of
snakes. Although only fragmentary remains are known, it is claimed to
have reached the immense length of 15-20 meters! This creature appeared
in the Cretaceous period and possibly dined on dinosaurs. It was similar
to today’s boas and pythons in that it was not venomous, but rather
squeezed its victims to death using its immense muscular strength.
Madtsoia was such a successful predator, that it managed to survive the
extinction that wiped out dinosaurs and other animals, but it finally
went extinct about 45 million years ago. Other giant snakes are known
to have existed, including one that was said to reach 29 meters in
length!
7). Purussaurus
Purussaurus was a gigantic caiman (a relative to alligators) that
lived in what is today known as the Amazonian rainforest. Back in
Purussaurus’ days, 8 million years ago, that region was actually a vast
inland sea teaming with crocodiles, gharials, fresh water whales, giant
rodents and enormous turtles. Purussaurus was the top predator in that
sea, and with good reason; at 12-15 meters long, maybe more, it was one
of the largest crocodilians ever to have existed. The remains of other
animals missing limbs or bitten in half are a macabre proof of this
giant caiman’s appetite.
6). Entelodon
Although pigs, wild boars and warthogs today are known to eat meat on
occasion, they are basically vegetarian. On the other hand, the
Entelodon, a prehistoric pig relative, was a full time carnivore and
possibly one of the most monstrous-looking mammals ever. Standing on all
fours, this beast was as tall as a man, and had an immense head armed
with powerful jaws and sharp teeth. Scientists believe that it was able
to hunt live prey, but that it also scared other predators away from
their kills (which should have been very easy). Its bite marks also
suggest that it fought viciously with its own kind, and it is even
possible that Entelodonts were cannibalistic. Entelodons were quite
successful beasts, existing for about 9 million years.
5). Azhdarchid
Azhdarchids were a kind of pterosaur (most popularly known as
pterodactyls) which included the largest flying creatures ever to have
existed. Some of them had wingspans of 12 to 15 meters, making them as
large as a small plane (although they were obviously not as heavy). But
what makes Azhdarchids really strange are their body proportions; they
had ridiculously long legs, necks and beaks, and very small bodies, as
well as relatively short wings. Scientists believe that they did not
hunt on the wing, but rather walked on the ground hunting for any animal
they could catch and swallow whole- that included dog-sized, perhaps
even man-sized creatures! Standing on all fours, the largest Azhdarchids
were as tall as a modern day giraffe… and almost as tall as a T-Rex.
4). Pulmonoscorpius
This is by far the smallest creature of the list, but it would still
cause hysteria, and perhaps even some heart attacks, if it showed up
today. It was very similar to today’s scorpions but could grow up to one
meter long, perhaps more, and was armed with sharp chelae (claws) and a
venomous stinger. Of course, we don’t know how toxic its venom was, but
considering the considerable amount it injected with each attack, it
was most likely a very deadly critter indeed. A predator,
Pulmonoscorpius roamed the swampy forests of the Carboniferous in what
is today Scotland. Just so you know, during the Carboniferous there were
also giant roaches the size of house cats, dragonflies the size of
hawks, and centipede-relatives up to three meters long. No kidding.
3). Xenosmilus
Since the formidable Smilodon (better known as saber-toothed tiger)
is too well known, we have decided to go for a refreshing change. Enter
Xenosmilus, possibly the nastiest feline ever to have existed. The
remains of this very large cat (the size of a lion or tiger, but more
robust) were recently found in Florida along with the remains of many
unlucky giant peccaries (similar to wild pigs) that fell prey to it.
Instead of strangling prey or breaking their neck as lions do, or
stabbing them as the sabertoothed tiger did, Xenosmilus acted more like a
shark or a carnivorous dinosaur, biting off a huge chunk of flesh and
causing massive blood loss and shock in a matter of seconds. Compared to
modern day felids, a Xenosmilus’ kill would probably be extremely
bloody; so much in fact that it would probably not be shown in Animal
Planet! Since we don’t know when exactly Xenosmilus became extinct, we
can’t tell if humans ever met this cat, or fell prey to it.
2). Megalodon
This is a fairly well known prehistoric monster, but it is just so
big and scary that it deserves to be in this list. Megalodon
(technically called a Carcharocles megalodon) was a gigantic shark,
closely related to today’s makos and great whites. It could grow up to
20 meters long and weigh up to 60 tons, being almost six times larger
than Tyrannosaurus rex! Obviously, the only thing in the sea big enough
to feed Megalodon where whales, and indeed, the giant shark’s bite marks
have been found in the fossil remains of whales all around the world.
Although many people like to imagine encounters between Megalodon and
T-Rex, or dinosaur-like marine reptiles, the truth is Megalodon appeared
long after the extinction of such creatures, and it wasn’t seen alive
by any humans either, although it was still roaming the oceans when our
australopithecine relatives took their first steps out of the jungle.
1). Spinosaurus
When Jurassic Park III was released in 2001, many people complained
that the beloved lawyer-eating T-Rex had been replaced with a “made up”
dinosaur. In reality, Spinosaurus did exist… and it was indeed bigger
than T-Rex. The remains of this enormous predator where found in Egypt
in 1915, and the paleontologist who studied them was already convinced
that it was bigger than T-Rex. However, this couldn’t be proved as the
fossils were sadly destroyed in a bombing during WWII. Recently,
however, new fossils have been found, and Spinosaurus was finally
declared to be the largest carnivorous dinosaur of all times. This
beastie could grow up to 17 or 18 meters long, weigh up to 10 tons and
had a sail on its back taller than an adult man. Its long,
crocodile-like snout suggests that it spend a long time in the water and
possibly ate lots of fish… but also crocodiles, giant turtles, and any
dinosaur unlucky enough to cross its path. Even though T-Rex will
probably always be the most popular prehistoric monster of all times,
Spinosaurus is, and remains, the largest predator ever to walk the
Earth… that we know of.