10 top facts about
C. megalodon
A
lot has been said about C. megalodon, and a lot of
it not always true.
So here are some condensed facts about this mighty shark that was once
the terror of the oceans. A quick note before we begin, this article
will reference C. megalodon in the correct and
standard way with
reference to the ‘C.’ denoting the genus and ‘megalodon’ the species
name, as opposed to just naming it ‘Megalodon’ as most other articles
do. Binomial names such as this always have two parts so that it is
easier to distinguish two separate animals, even when they have either
the same genus or species name, that is why it is important to write
both, even if the genus name is abbreviated to just the first letter.1 - C. megalodon is only known from teeth and vertebrae.
There
have literally been tens of thousands of C. megalodon
teeth
discovered, ranging from partial crowns to almost complete sets. So
numerous are C. megalodon teeth, that more are
discovered every day
and no one can put a precise figure upon how many exist, and is why
C. megalodon teeth are popular items for fossil
collectors, even if
they are still substantially more expensive to buy than other fossil
shark teeth.
What
is not so well known is that there are actually some vertebrae of C.
megalodon that are also known, and in rare examples near
complete
spinal columns have been discovered. Unfortunately we do not yet have
any other clues as to the appearance of C. megalodon,
mainly
because shark skeletons are cartilaginous and decompose quickly.
Vertebrae are sometimes preserved because the cartilage here usually
has a higher degree of ossification (closer to actual bone),
while teeth, the hardest parts that are covered with hard enamel are
the most likely parts to survive long enough to be fossilised.
2 - The debate about the correct genus classification for C. megalodon has been going on for almost two hundred years.
In
1843 the noted Swiss naturalist Louis Agassiz formerly described
the teeth of C. megalodon as belonging to the Carcharodon
genus,
establishing the full name of this shark as Carcharodon
megalodon.
This was based upon a superficial resemblance between the teeth of C.
megalodon and the teeth of Carcharodon carcharias,
much better known
as the Great White Shark, the largest known hyper-carnivorous shark
alive today (larger sharks such as the basking and whale sharks are
filter feeders). Because of this original classification, C.
megalodon has been dubbed as not only a close cousin to the
great
white shark, but even the probable ancestor too it.
Not
everyone was convinced however, and especially in
modern times less and less people are becoming convinced about
this old classification. The first problem with the notion that C.
megalodon was the ancestor to the great white shark is that
both C.
megalodon and the great white are known to have co-existed
in the
world’s oceans for many millions of years. This does not completely
discount the idea of the great white being descended from C.
megalodon, but it led to an alternate theory that C.
megalodon and
the great white may have had a common ancestor.
This
was still not enough for many though. While the teeth of C.
megalodon and the great white are both large and
triangular, there
are still several differences in form and curvature, and these are so
great they are taken as some as clear signs that C.
megalodon does
not belong within the Carcharodon genus. This led
to the proposal
that C. megalodon should be moved into the Carcharocles
genus,
something that at times has led to fierce debate from those who
insist that C. megalodon should remain within the
Carcharodon genus.
However new analytical techniques combined with new shark discoveries
such as Carcharodon
hubbelli suggest that the great white shark is
actually descended from mako sharks, and with no known link between
megatoothed sharks like C. megalodon and mako
sharks, this may well
indicate that C. megalodon really does belong
within the Carcharocles
genus.
3 - C. megalodon were the largest sharks known to ever exist...
There
is little doubt to the validity of this statement, C.
megalodon
fossils incorporate some of the largest fossil teeth of any known
shark, and the vertebrae too indicate a physically large size for the
body. There is no definitive known size however as size estimates
depend mostly upon the teeth. Some scientists measure certain lengths
and ratios of the crown and compare them to other shark teeth to
establish a correlation between tooth size and body size, but there
are several different mathematical formulae for doing this, and often
they yield different results, even when applied to the same
specimen. Other times complete jaws have been assembled from complete
sets of teeth, and the remainder of the body scaled to the width of
the gape.
In
short the methods of establishing the size for C. megalodon
are many
and varied, but most palaeoichthyologists (like palaeontologists
but specialising in fossils of fish) agree that a total size of
around fifteen meters long is certainly attainable for the largest C.
megalodon specimens. Even larger estimates from some
researchers
however suggest that C. megalodon may have grown
even bigger with the
largest individuals approaching anywhere within the region of seventeen
to even twenty meters long. Still, even at the smaller fifteen
metres mark, C. megalodon is still much bigger
than any other known
shark, whether alive today or in the fossil record.
4 - ...but C. megalodon were not the only giant sharks.
C. megalodon were big, no doubt about it, but there were other monster sharks swimming in the prehistoric oceans. Other megatoothed sharks such as C. angustidens and C. chubutensis were almost as big as C. megalodon, and still much bigger than the largest recorded great white shark. Also before even C. megalodon appeared, members of the shark genus Otodus were cruising the oceanic depths. Earlier than this back in the Cretaceous sharks such as Cretoxyrhina had also already exceeded the largest known modern day examples of the great white shark. What this proves is that even though C. megalodon was the biggest, the sharks have a very real capacity for growing to large sizes.
5 - C. megalodon teeth were once thought to be dragon tongues.
It’s
true, many hundreds of years ago large fossilised shark teeth like
those belonging to C. megalodon were thought to
be the petrified
tongues of dragons (and alternatively large snakes, large examples
of which were often seen as ‘serpent dragons’). The idea was that
a dragon lost the tip of its tongue either through shedding, combat
or just death, and that after it left the body the flesh had become
petrified. The word petrified is actually a combination of the
Ancient Greek words for ‘stone’ and ‘turned’, and it’s
possible for organic matter such as the wood of trees to become
petrified and turned to stone. So, the idea that dragon flesh had
become petrified was actually a fairly intelligent interpretation of
how these ‘tongue stones’ or alternatively ‘glossopetrae’ had
formed, albeit they were wrong about the dragons. Because of their
believed connection, these stones were believed to protect against
and cure the effects of snake bites and poison.
This
interpretation was a common belief until the 17th century. The
first attempt to classify these fossils as shark teeth came in 1616
in De glossopetris dissertatio by Fabio Colonna, but it was not
until 1667 when Nicolaus Steno, a Danish naturalist published his
work The Head of a Shark Dissected that the truth about these fossils
became more widely accepted. The knowledge that these tongue stones
were really sharks teeth quickly disseminated throughout the scientific
and educational bodies across Europe, and eventually this filtered to
other areas of society.
6 - C. megalodon were whale killers.
Nine times out of ten, a big predator needs big prey, and the only animals that were both large and numerous enough to satisfy the appetite of C. megalodon were whales. This is not just blind supposition however, whales were at their most diverse and numerous during the Miocene era, and many whale fossils have been found with marks on them that could only have been caused by the tips of large shark teeth, like those that C. megalodon had. More interesting than these however are whale vertebrae which have partial damage upon the bottom that shows these vertebrae were impacted together as if hit from below by a large predator. It’s possible that C. megalodon may have struck smaller whales from below in a similar manner to how a great white shark will strike a seal from below today. With the prey stunned, a C. megalodon would have time to turn around and finish the prey with a powerful bite. Larger whales that were themselves too large for such a tactic may have still been attacked by C. megalodon, but in these instances the shark would attack the tail fluke and fins, immobilising the whale so that it could not swim away, thus allowing the shark to eat at its own leisure.
7 - Large C. megalodon probably had the strongest bite of any known living creature.
As a big predator C. megalodon would have had a big mouth, and comparison to other sharks indicates that the jaw closing muscles of C. megalodon would have been colossal. One noted study (S. Wroe et al, 2008) established a range of about 108,000 - 182,000 newtons (11 - 18.5 metric tons) posterior bite force (bites are strongest nearer to the point of jaw articulation due to force focusing) for lower and upper maximum size estimates of C. megalodon. This study was based around the jaw mechanics of the great white shark, which in turn led to the largest known example of a great white shark having a bite force of 18, 216 newtons (1.85 metric tons).
8 - C. megalodon lived in oceanic waters across the globe.
C.
megalodon is known to have had what is termed a cosmopolitan
distribution because fossil teeth of this shark have been discovered in
age appropriate coastal/marine rock deposits all over the world. The
only exception to this idea is that so far C. megalodon
teeth have
not been found around waters of the extreme north and extreme south,
waters that would have been much cooler than those near the equator.
This has led to the suggestion that C. megalodon
may have had
metabolisms that operated faster than typically ‘cold-blooded
animals, and had to stay in warmer and more temperate waters where
they would not have needed such a large calorie intake to maintain this
metabolism.
9 - The most recent known fossils of C. megalodon are roughly 1.8 million years old.
C. megalodon had a very broad temporal range with fossil teeth going all the way back to the late Oligocene, and not disappearing from the fossil record until the late Gelasian period of the Pleistocene some 1.8 million years ago. However there was once a rare exception to this with a fossil C. megalodon tooth (one of at least two) that was first discovered in 1872 during a voyage by HMS Challenger. When tested in 1959 this tooth was credited as being only 10,000 years old, making it supposed proof that C. megalodon only went extinct in recent times. However, the 10,000 years date was worked out by measuring the level of manganese dioxide build up upon the fossil specimen, and today we now know this to be a highly unreliable method of testing age because the level of manganese dioxide on two fossils of the same age and can vary wildly. When the tooth was re-tested with radio carbon dating, a clear result could not be achieved, but this in itself would indicate that the tooth was much older than 10,000 years. For the record, at the time of writing even the most advanced and experimental radio carbon dating techniques can only give a date if a specimen is less than a few hundred thousand years old. When fossils are established as being many millions of years old, it is usually from establishing the age of the rocks that they have come from.
10 - C. megalodon is now one of the most popular prehistoric animals to feature in popular fiction.
Whenever
people first hear the name C. megalodon,
usually just as
‘Megalodon’ it’s usually within the context of an appearance in a
film, novel or other work of fiction, and that’s no real surprise.
Although C. megalodon was first named in
1843, for the first
hundred and fifty years it received surprisingly little attention,
and when it did it, it was usually just as ‘giant shark’. From
the 1990‘s onward however, and coinciding with the rise in
internet access and use for the first time, C. megalodon
quickly
began to occupy the public’s imagination. With a public demand for
more information (and much easier and cheaper access to computer
special effects), C. megalodon has been
featured in everything
from written fiction such as novels to low budget films and
Discovery Channel ‘documentaries’ (stop laughing!).
Part
of this interest can actually be traced back to 1975 with the
cinematic release of Jaws, though this was actually just one of many
‘killer shark’ movies from the 1970s. Since this time stories
featuring abnormally large and aggressive sharks going on a rampage
have become standard B. movie fodder, and worldwide there are now
literally hundreds of such films. With C. megalodon
credited as
being the largest shark, it is both monstrous yet familiar enough for
people to recognise.
Unfortunately
beyond the name and large size, most writers and producers don’t care
to be factually correct about C. megalodon.
Across various works of
fiction C. megalodon is often portrayed as much
bigger than it
actually was, something that used to hunt and kill dinosaurs,
something that ‘was’ a dinosaur, capable of leaping thousands of
feet out of the water, having the power to sink even big
warships, lying dormant and frozen in icebergs and still living in
the deepest darkest depths of the ocean. Because these works of
fiction have often been the first and even only introduction that
people have had to C. megalodon, they are often
taken as
‘truths’ and passed around as such.
Films
and books that are intended as stories for entertainment are no real
problem, when written well they can be very entertaining even with
scientific inaccuracies. What
is disturbing though is the development of the ‘fake-umentory’, a
television show presented as a factual documentary yet is actually
composed of faked footage with actors portraying the scientific
‘experts’ and ‘witnesses’ for the purpose of
‘entertainment’, and although brief disclaimers about the shows
are aired during broadcast, these are often very short and more often
misunderstood by the viewers. Most infamous was the Discovery
Channels Megalodon: The Monster Shark Lives,
though with this
feature fast becoming one of the Discovery Channel’s more popular
shows (thanks largely to its infamy), and a follow up 'documentary'
a
year later, it is easy to understand
the great temptation of more unscrupulous television producers to
substitute fact for fiction. Remember, as with all things, never
rely upon only one source for your information.
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