Large Marine Predators from the past.....

Date : 20 may, 2015
Version: 0.1
By: Albert van der Sel
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Large marine predators from the past...

Let's take a quick look at PredatorX, Megalodon, Tylosaurus proriger (Mosasaurus), Livyatan melvillei,
Kronosaurus, Liopleurodon, Basilosaurus, and the "Dorset pliosaurus".

Let's spend a few words on the most awesome Predators from the Seas, across all times...
I don't say that this list is complete, or representative, or whatever... It's just my personal findings.

1. Pliosaurus Funkei (PredatorX).

Yes, sometimes I flashback to be 8 years old, or something.
But..., "Predator X", or officially named "Pliosaurus Funkei", is quite awesome !
Was it the "top" marine Predator? It's very powerfull indeed, but wait until you have seen, for example, "Livyatan"
or the "Dorset pliosaurus".

I often study the predators from the past, just for fun (if you think that's weird.., then you are probably right.).

If we focus for sea animals for a moment, then for sure, a few champions were:
"Megalodon", "Tylosaurus" or "Hainosaurus" (both Mosasaurs), "Basilosaurus", "Kronosaurus", and "Livyatan".
And, relatively new is the discovery of the "Dorset pliosaurus".

They are all Big! For example "Megalodon" was a highly enlarged "white shark" type of predator, with a (conservative) estimate length
of 17m, and a weight that's often estimated to be in the range of somewhere between 50 and 100 tons.
That seems really a lot of weight! If you would ask me, I believe it's more towards the "50s" instead of the "100s".

If Megalodon's mouth is fully open, a car can easily pass through, and indeed, the large arrays of enormous teeth, convinced many
folks, that "Megalodon" was the apex sea predator of all times.

Then, I sort of "re-discovered" Predator X a bit. Let me explain that. I often read that Funkei was probably at most 15 tons or so.
But the numbers fluctuated quite a bit over time, depending on the size of the animal. Originally being oversized, the numbers went down,
and later went up a bit, slowing reaching some sort of "consensus" nowadays, while never being fully convincing for all scientists involved.

During that period, several sources mentioned estimated weights in the order of over 30 tons for Funkei.
That actually seems way too much.
That's a lot of a difference compared to 15 tons! If true, that will place the animal into a completely other class
with respect to the combination of weight/length/bite-force. I instantly started to like Funkei much more from that fact.
But it was wrong.

Not all statements on Funkei, are without some controversy. The actual fossile "hard" data is rather limited, and possibly
some of the remains actually belong to different species. Usually, extrapolations, and examples from other animals, are used to
fill in some of the "gaps".

As it turned out, the 30 tons apply for an animal of about 15+ meters. Well, nowadays Funkei is estimated to have had a maximum lenght
of about 13 meters (or a little less), thus the tonnage dropped much more quickly then the lenght.

Fig. 1: Pliosaurus Funkei (PredatorX)

Today, it seems that there is more or less a consenus for the numbers "max 13 meters" and about max "10 to 15" tons for Funkei.

One special difficulty in sizing Pliosaurs, was how to relate the dimension of a skull, to the rest of the body, if only partial
data is available. On some moment, scientists found that for most of the larger Pliosaurs, that they have a relativly large skull
compared to the body. This in contrast to the long-necked plesiosaurus. Since it was accepted that the Pliosaurs have a compact body
relative to the skull, the sizes shrunk substantially.

"Downsizing" of marine predators of the past, is/was not uncommon. Due to lack of substantial data,
it has "plaqued" various Pliosaurs and Mosasaurs to name a few. But the latest numbers are probably close to reality.

However, "even" with "only" 13 meters of length and a weight of (say) 10 tons, Funkei still remains a formidable predator.
Indeed, the number of tons drops quickly, if the size is relatively slightly reduced. See the note at the end of this page.

Table 1: Some data on "Pliosaurus funkei":

Period: Approximately 145 to 150 million years ago.
weight: Possibly up to 15 tons. Conservative estimates speak of up to 10 tons.
Length: Likely to be at a maximum of 13 meters.
Teeth: Largest teeth about 30 cm.
Bite force: Very high. No true consensus seems to exists. Very likely to be substantially more than that of T Rex.
Further characteristics: The front flippers, are somewhat larger than other pliosaurs. Short neck. Very robust posture.

2. Megalodon.

If you take notice of the periods mentioned in tables 1 & 2, we see that Megalodon could not have met Funkei.

Megalodon is so huge and heavy, that many folks consider it to be the #1 predator in the seas, of all times.
Essentially, it's a very enlarged "white-shark" like animal. And a "shark" it is.
With a length that is often estimated to reside somewhere in 15m to 20m, it seems pretty save to assume 17m for an
healthy adult animal. It's weight is then believed to be somewhere in between 50 and 100 tons.

So, a 70 ton Megalodon, is ten times heavier than an adult T Rex.

It's likely it preyed on whales of all sizes, especially the medium sized to the very largest ones.
One speculation (but with good reasons to assume so), is that it "stormed" at it's prey, took a horrible bite,
leaving it's victim in shock (or already almost dead). Then it waited for it's victim to pass away, and what then
followed, I really dare not to write down.

Smell, and especially, what most sharks have, a high sensitivity for pressure variations in the water, were probably it's
main detection sensory systems for locating prey. It cannot be excluded that sensitivity for electromagnetic fields
was in it's arsenal too (since many marine biologists think that sharks posess that ability).

With a open mouth, that's easily more than 2m accross, it's bite-force would have been immense indeed.
I have seen very conservative estimates of about 15 tons.

Table 2: Some data on "Carcharodon Megalodon":

Period: From about 20 million to about 1.5 million years ago.
weight: Likey to be between 50 to 80 tons (80 tons for a 20m animal).
Length: Likely to be between 15m to 20m. Conservative estimates speak of a max of 15, 16 meters.
Bite force: Likely to be somewhere in between 10 and 19 tons. Different studies show quite some variations.
Further characteristics: A "White Shark-like" appearance.

Fig. 2: Megalodon: reconstructed jaws, and a comparison with T Rex.

3. Mosasaurs: "Hainosaurus" or "Tylosaurus proriger".

For this large family of members, it is one of the most difficult families, to determine it's largest subspecies.
And, what happened with other species as well, downsizing (and occasionally upsizing) of certain Mosasaurs
happened quite frequently too, especially for the large members.

The largest Mosasaurus might have been "Hainosaurus", or possibly "Tylosaurus proriger", or
possibly "giant Mosasaur". Of the latter, it is quite possible that it is only a synonym for one of the first two animals.

While "Hainosaurus" and "Tylosaurus proriger" were first estimated to be well over 15 meters long, later "revisions" all
all hover somewhere between 12m - 15m. Strange thing is though, that a few reconstructed skeletons are at least 15m long,
but possibly some were slightly "flawed".
But, quite a few reliable (and recent) articles maintain that "Tylosaurus proriger" could reach 50 ft (15m) of lenght.

Since the determination of "raw power" we are looking for, strongly depends on the weight and length of such an animal,
it's really hard to compare such Mosasaurs with other champions, like for example "Predator X" or "Livyatan melvillei".

However, surprisingly, a large speed sometimes is attributed to "Tylosaurus proriger", or, rather explosive accelerations.

But is seems that all of the larger Mosasaurs, are somewhat more slender, and with a longer tail, compared to the rather bulky PredatorX.
It seems reasonable to assume a minimum length of 14m, and a weight of at least 20 tons, for the largest Mosasaur, like "Tylosaurus proriger".

Table 3: Some data on "Tylosaurus proriger":

Period: Many say 85 to 65 million years ago. Other estimates speak of 70 to 66 million years ago
weight: Possibly 20 tons. More conservative estimates speak of about 15 tons.
Length: Likely to be around 14 meters. Many scale it to be actually 15 meters.
Bite force: Could not find any consensus. Likely to be the same as Funkei's, or possibly a little lower.
Further characteristics: Sometimes described as a fast (or "explosive") swimming animal.

Fig. 3: "Tylosaurus proriger".

4. Livyatan melvillei (mammal, whale).

Maybe you would call it a Super "Orca" (Killerwhale), or Super "sperm whale", since, indeed, a tooth-whale it was.
It's a very distant relative of our present day sperm whale. The physical appearance is likely to match too.

If it hunted in packs (families or otherwise), then such a pack might have been the most powerfull "unit" ever...

Even if you "are" Megalodon, and you would have met a pack (if true) of Livyatan, there is no way to say what followed then,
but it seems fair to asssume that it would end in "goodbye Megalodon".
But even a solitary adult, would probably have been a serious opponent for Megalodon.
Since Livyatan lived about 1213 million ago, it really could have met Megalodon on occasions.

Estimated to have a length between 13m and 17m, it seems save to assume a length of 15m for an adult specimen.
It's weight, of an adult of 15+ meters, would then have been around 50, 55 tons or so.

All further specs seem to be comparable to our present day sperm whale, but this time, the whale had an extremely impressive array
of very large teeth (about 36 cm) in both upper and lower jaws.

I could not find real confirmation of the fact that it lived in packs, but it is very likely that it did.
Also, I could not find a reliable estimation of it's "bite-force", but clearly, it was immensly high.
For example, If we claim that PredatorX, and similar, probably have a bite-force of several times that of T Rex, then for Livyatan,
it must have been out of scale (so to speak).

Livyatan had more or less the same resonant cavitities, or the "melon", in the front of it's head, as present day whales have, suggesting
an advanced form of the ability of having echo-location.
Using "clicks" or other whale-like music, might gave Livyatan another advantage above other predators.
It's not impossible (but it's completely speculative), that Livyatan detected Megalodon, before Megalodon detected Livyatan,
and Livyatan kicked it's ass.

So, in the search of the most powerfull predator in the seas, across all time, Livyatan is a promising candidate.

Table 4: Some basic data on "Livyatan":

Period: Estimated to have lived about 12 million years ago.
weight: Likey to be in the range from 50, 55 tons (for a 15m animal).
Length: Likely to be around 50 feet / 15 m.
Bite force: Have not found solid estimates. Likely to be extremely high.
Further characteristics: Very large teeth (36 cm) in upper- and lower jaws. Likely to have lived in groups (families?)

Fig. 4: Reconstructed skull of Livyatan melvillei, and general appearance.

5. Liopleurodon Ferox.

This animal was the subject of rather extreme variations in it's dimensions like length and weight.
Once, ideas were launched of a 20+ meter long animal, weighting far over 100 tons.
So, here then: did we finally found the Super Predator of all times?

More thourough research gave substantial lower figures. Today, Liopleurodon's length is estimated to be
anywhere between 7m - 12m. Quite a few paleontologist keep the size within 6.5 to 7.5 meters.

One rather difficult element in any research, is the ratio between the size of the skull (or fragments) in relation to the
rest of the body.

For example, many "pliosaurs" have a relatively large skull, with a compact body.
In contrast, the long-necked plesiosaurus have a relatively smaller skull, with a long neck, and a stretched body.

Today, for Liopleurodon Ferox (the largest subspecies), it is said that it was short-necked too,
with a skull up to 1.5 m lenght.
It won't be our top predator (that is: in my listing here), but it sure was an impressive predator.
It's protruding frontteeth gave Liopleurodon a remarkable appearance.

Table 4: Some basic data on "Liopleurodon":

Period: about 160 million years ago
weight: Probably not more than 5 tons (10m). Likely to be less, like 3 tons (if the length is max 7.5m).
Length: often estimated to be somewhere in 7m - 12m. Conservative estimations speak of 6.5m - 7.5m.
Bite force: Unknown. But likely to be way less than that of Funkei or Kronosaurus or Tylosaurus proriger.
Further characteristics: Relatively slender, probably capable of large accelerations.

Fig. 5: Reconstructed skeleton of Liopleurodon Ferox., and it's general appearance.

Yes..., Liopleurodon Ferox..., from the data above, it seems to lack some serious fire-power.

Was it really only between 6.5 - 7.5 meters long? Or, as some other modern interpretations go: having a max of about 12 meters?
It really makes a differenence. 12 meters, would place it in the same range as Kronosaurus or Funkei.
Although a lenght of 6.5 - 7.5 meters, and a tonnage of 5 tons (if 6.5 - 7.5 meters would hold), is still impressive,
it is pretty "tiny" compared to Funkei (13m/25tons).

I don't like to talk in the following way, but a Pliosaur of 12 meters, completely annihilates a 7 meter animal.
The difference in mass (and bite-force) is so large, that it is a completely unfair "battle".

But we can't deny it: there still are some clouds over the true dimensions of "Liopleurodon Ferox".

As scientists themselves say it again and again: be very carefull about statements of sizes and weights.

Indeed, it's only obvious that my text here, might have nasty glitches too....

In the reconstructed skeleton of figure 5, we can see a relatively long neck, and quite a streched torso.
If a recovered skull was indeed about 1.5 meters long, it would not surprise me if it turned out it was actually 12+ meters.

6. Kronosaurus.

Now, let's see about Kronosaurus... and other amazing pliosaurs..

Deeply rooted in Pliosauroidea, came several "branches" of "lizard like" animals (they were not dinosaurs).

- A few branches from the root, we have the (often) long-necked "Plesiosaurs". Although some specimens could reach considerable lengths,
they never impressed me too much (from the perspective of "power", which, I admit, is a bit silly ofcourse).
A large part of the animal, is the long "neck", and they probably missed the large muscles behind the skull, needed to reach a high bite-force.
Ofcourse, they are great and amazing animals, but I think not the animals if one is searching for "power" (again: sorry!).

- Another branch are the "Pliosaurs".
Often, they have big skulls on compact bodies, but not in all cases.

We already have met one of them: Pliosaurus Funkei. But there were many others as well, and some were large too.

There has always been, and even today there is, some level of "foggy" conditions around the large pliosaurs.
Partial fragments have been found, in Australia, Mexico, Norway, and many other places.
Some fragments even seem to hint at skull sizes of 3+ meters (!)
If true, then we might be looking at an animal of about 16 meters, which will throw a bombshell on any note comparing marine Predators.
In section 8, I plan to present some material on the "Dorset Pliosaurus", but I am still not sure if I can collect enough
trustworthy material.

One reasonable "complete" skeleton was found in the '30s of the former century. The animal was called "Kronosaurus queenslandicus",
or also know as "Kronosaurus". Over the years, a rather large debate spun off with regards to the true dimensions of the animal.
The values moved between a minimum length of 8 meters, and a maximum lenght of 15 meters.

The skeleton resides at Harvard University, and it shows a pliosaurus of an incredible length (and it's weight would have been enormous too).
Take a look at figure 6 below, and hold your breath!
As we have seen in the theory above, the skeleton is probably too long, possibly by adding too much vertebrae.
However, even if the length is shrunk by a few meters, but if the skull retains it's dimensions (likely so), then Kronosaurus
belongs to the top predators of all times.

Fig. 6: Reconstructed skeleton of "Kronosaurus queenslandicus", and a picture illustrating relative sizes before/after corrections.

As it is today, we have Funkei with a max lenght of 13 meters, and Kronosaurus, which currently is believed to have reached
a max length of about 11 meters.

Whatever scientists may say about the dimensions of Kronosaurus: the skull (as shown in figure 6) is large..., really large.
And that is a real skull.

I'am quite sure the chapters on Funkei and Kronosaurus are not closed yet. The skull of the "Dorset" one (as we will see in section 8),
does not strike me as particularly much larger as Kronosaurus.

Table 6: Some data on "Kronosaurus":

Period: Approximately 110 million years ago.
weight: Possibly up to 10 or 12 tons. Some claim that it is considerably more.
Length: Likely to be around 9 to 11 meters. Some say that it is a little more.
Bite force: Very high. No true consensus exists. Likely to be a little lower than funkei's.

7. Basilosaurus or "Zeuglodon" (mammal, whale).

Again, here we have mammal, sort of the very first (large) "whale like" animals in the seas.

It will not be our top predator, since I think that "Livyatan melvillei" (a whale too, see section 4),
is probably more powerfull than Basilosaurus.
Basilosaurus (or "Zeuglodon" as it was renamed since it was not a "saurus" as previously assumed), was master
of the oceans about 34 million years ago.

Basilosaurus is certainly not a small one. It's dimensions are pretty awesome, although it's rather "slender".
It's often estimated to have had a lenght of about 14 meters to 20 meters, and a weight that is often estimated
to be somewhere in the range of 30 tons to 60 tons.

Most paleontologist involved in research of this animal, strongly suggests it was about 16m to 18m long.

It was a "tooth" whale, and indeed, it had an impressive skull, and probably a high bite-force too, although the array
of teeth is less impressive compared to those of "Livyatan".

Since it was one of the first large whales in the seas, it's assumed it was less social, and probably less intelligent,
again, compared to "Livyatan".

However, it was a Predator, and although it lived in a timespan that does not overlaps with all of the predators above,
we still may compare it's "power" with all of the animals above.
However, as usual, it's very difficult to do so. I already explained several times at various places in the text above,
that it is rather "silly" to use a perspective of "weight/length/bite-force" only, and ignoring all other fantastice aspects
of those animals. Absolutely true. That's silly ! However, this text has as it's goal to find the top marine Predator(s)
of all times, so there it is... (the value of this text: it's very limited!).

I don't think this animal is in the "class" of "Livyatan" or "Megalodon". How it would size up to the large Pliosaurs or Mosasaurs?
Ofcourse I can't say, but I would bet that the "power" of this animal would be comparable to the very largest of the Mosasaurs.
All in all, a fantastic creature and absolutely very very strong.

Fig. 7: Basilosaurus.

8. The "Dorset pliosaurus".

We already have seen two great pliosaurs: "Kronosaurus" (section 6), and "Pliosaurus Funkei" (section 1).

Funkei, is probably the pliosaurus of which remains were found near "Svalbard" (Arctic Ocean), and was first dubbed "Predator X".
Originally, it's lenght was estimated to be in the range of 15m, but was later "corrected" to be in the order of max 13m.
Funkei's remains were rather scarce, and rather distorted.
But the remains of the skull, really hinted at a skull size of near 3 meters, which is awfully large.

Kronosaurus queenslandicus was found near Queensland, Australia, and the fossilized remains were rather distored too.
It's skull size was estimated to be in the order of 2.7 meters.

Recently (april 2015), an Australian farmer found a 5 foot jawbone, now believed to have belonged to a baby "queenslandicus".

Indeed, as time progress, scientists will gradually learn more and more about the large Pliosaurs, and the picture will
get more and more complete.

Now, what about the "Dorset pliosaurus"?

I mention this one only, since it might be potentially the largest one ever discovered sofar.

Late in 2009, palaeontologists discovered remains of a pliosaurus near Dorset, on Britain's Jurassic coast.
The fossil had a skull length of 2.4 meters, and the fossil hinted to a body length, of what could have been a maximum of 16 meters.
The total lenght is still under discussion, and nowadays still seems to hover between 12 meters and 16 meters long.
What I seem to observe, is that again an initial large estimation, seems gradually to converge to something like 12m or so.

Ofcourse, the finding adds to the data about large pliosaurs in general, and that this one might potentially have been 16m long,
makes it really noteworthy.

The only thing that "worries" me a bit is the size of the skull which is about 2.4 meters, and thus seems to be a little
bit smaller than what seems to be the case with Funkei or Kronosaurus. But it's still a large skull ofcourse.

To my knowledge, it's still not completely clear where in the "tree" of subspecies the "Dorset pliosaurus" has it's place.

It certainly has not to be so, that all large pliosaurs in the incredable long timespan of 155 million years to 140 million years ago,
"per definition" perse have to have had the same skull dimensions relative to the body.
But if the Dorset one, ultimately is estimated to have been 15+ meters, than an explanation for the relatively smaller skull has to be found too.
That is, if it's indeed a subspecies very close to Funkei or Kronosaurus.

If it would be more "close" to Liopleurodon, it would make more sense.

The long subtrees of Pliosauroidea, also incorperates the "Plesiosaurs" (usually the animals with the long neck).
It seems to be established that the "Dorset one" does not belong to that subclass.

9. What did I left out?.

Yes, many other large Predators roamed the seas in the past. Ofcourse we haven't seen them all here.

For example, many other large sharks were around during those many millions of years in the past. But Megalodon
was undoubtly the "worst", so I kept this text limited to that one.

The same holds for Mosasaurs and Pliosaurs, and here too, I think we have seen the "champions" (as we know of today).

You may see in other docs, many other large marine animals.
But don't forget: my text was solely about Predators.

Some examples of marine animals I left out:


However, some large predators I left out on purpose like for example "Shonisaurus", which was a predator indeed (Ichthyosaurus).
But, it was likely not a "fierce" predator, like equiped with large teeth and anythink else that makes it a terrible predator.
Ofcourse I don't mean "terrible" here in the usual meaning, but something more in the way of "terribly impressive...".
But it could reach a large length indeed, maybe up to 17m or so.


A large prehistoric shark was "Cretoxyrhina", which was comparable to our present day White Shark, and probably even
slightly larger. But it was certainly not as impressive as "Megalodon".

-"Dunkleosteus terelli"

Indeed, a very impressive fish, with a mouth resembling a sort of large "wire cutter". Estmates of it's lenght varies between 5m to even 10m.
If it was substantially larger than 5m, it indeed was a good candidate for any sort of listing like this note is.
If you are unfamiliar with this fantastic animal, please do websearch. You will not be dissapointed.


Again, an enormous "fish", with an estimated lenght of possibly up to 13m.
But it was hardly a predator, so, not a candidate at all.

So yes. My text was indeed only a selection, but I think they were the best ones (that I know of).

10. So, what was the "Top" marine Predator?

I really can't tell.

Until recently, I would have voted for Megalodon. Today however, I believe I would go for "Livyatan melvillei".

That's it ! Hope you liked it !


Why does the mass of a Predator drops rather "sharply", if the length is somewhat reduced?
Suppose we take a look at a Pliosaurus. It's shape not an "ellipsoid" ofcourse, but as a crude approximation,
we just take an "ellipsoid" as an example.
I admit that this approach "stinks" somewhat, and is not realistic.
However, if we crudely approximate a predator to a larger, thinner ellipsoid, then at least we get an "order of magnitude"
approximation of the weight, associated to the dimensions.

- Suppose we have PredatorX (#1) with the following dimensions:
A=1m, B=1m, C=15m (where C is the axis in the "length" direction, A en B are perpendicular to C, and all axis are through the center/origin of the ellipsoid).

The volume would be (about) V1=4/3 x 3.14 x A x B x C = (about) 62 m3.

- Suppose we have PredatorX (#2), shrinked, with the following dimensions:
A=0.8m, B=0.8m, C=12m (where C is the axis in the "length" direction).

The volume would be (about) V2=4/3 x 3.14 x A x B x C = (about) 32 m3.

- Suppose we have PredatorX (#3), shrinked, with the following dimensions:
A=0.7m, B=0.7m, C=10m (where C is the axis in the "length" direction).

The volume would be (about) V3=4/3 x 3.14 x A x B x C = (about) 20 m3.

Indeed, Volumes "goes" by length x height x width, so if the axises are reduced somewhat, the Volume drops much more.
And, the mass of an animal is dependent on it's volume. With "water", it would correspond to the number of tons.

Since a pliosaurus would "fit" rather easily in such an ellipsoid (with quite some empty space left), for a (hypothetical) pliosaurus of 15m,
60 tons is way too much, and something like 20 to 30 tons or so, seems more reasonable and realistic.
Don't forget that the (small) tail contributes to the total lenght too.

For a Kronosaurus "like" animal of 10m (tail not counted), 20 tons looks way too much, and something like 10 tons or so,
seems more reasonable and realistic.

Ofcourse, such a volume calculation is v=4/3 π abc, and when a=b=c, we just have a sphere,
where v=4/3 π r3 which is the well-known volume formula for a sphere.