for many good reasons you are probably much more willing to be dropped into the middle of nowhere on land rather than in the ocean or sea after all it does appear that once you venture Into the Depths Life Starts to become more disturbing and this seems to be a common Trend throughout history as every point in time often has an animal or two lurking around in the waters that was Far scarier than anything found on land one documentary that nicely sums this up is sea monsters which made a list of the top 10 deadliest Seas or oceans of all time among those mentioned included Jurassic Waters home to Giant pliosaurs prazo oceans filled with giant seop pods and sea scorpions and even azoic sea that was home to the largest shark of all time however all this paled in comparison to their winner a body of water that existed during the leag Cretaceous that was home to numerous animals that would put much of the Marine predators of today to shame some of these beasts were included in the documentary yet many didn't make the cut despite definitely being worthy of tingling your thalassophobia and adding more reason as to why this body of water was absolutely the worst place to go swimming ever welcome my friends to the Western interior Seaway or as some people like to call it hell's aquarium while you may have never heard of this prehistoric shallow ocean or Inland Sea there is a fair chance you've walked across it or at least what's left of it if you live in the United States Mexico or Canada because when it was filled with water it split these count countries across basically drawing a line through most of North America and in the process it created two Island continents that no longer exist lamyia which lay to the west and Appalachia that stood to the east this state of existence persisted for roughly 34 million years from the early Cretaceous 100 million years ago all the way to the earliest paleocene Epoch 66 million years ago throughout this time sea monsters could be found at every point but some periods were unarguably worse than others with the Western interior Seaway having reached its Climax and Peak neness during the campanian age of the late Cretaceous spanning between 83. 6 and 72. 1 million years ago at the time the Seaway was warm and tropical in nature while spanning 600 M or 970 km at its widest point and measuring over 2,000 Mi or 3,200 km long additionally it was remarkably shallow for its size possibly only being 900 M or 3 ,000 ft deep at its deepest point compared to its presumed average depth of around 50 m or 150 ft yet despite its smallish size the Western interior Seaway still managed to cram in a ridiculous amount of nightmarish predators that were routinely larger or scarier than any of the predatory dinosaurs seen on land by far the most famous of these aquatic monsters and likely the worst to swim into were the mosasaurs this was an extinct group of aquatic reptiles that could grow to massive sizes and were characterized by body shapes similar to that of monitor lizards however unlike their modern-day relatives most thesaurus had four paddle-like flippers instead of Limbs and their bodies were elongated and streamlined for maximum drag reduction depending on how advanced the set species was these guys would have also swam like an eel in an undulating fashion or as in later developed mosasaurus like a shark as they had larger tail flukes that they used to propel themselves with surprising speed these powerful swimmers completely dominated the Western interior Seaway often being the biggest predators and sporting highly specialized teeth that were typically large sharp and sometimes serrated their success ultimately resulted in them enjoying a high level of diversification that they didn't experience anywhere else as over tengen a are known to have coexisted all at once ranging from 2 m or 6.
5 ft to possibly 18 M or 59 ft in length but despite their diversity chances are you'd only be attacked by three kinds the platic carpus dases and Tylosaurus as together they represent the most abundant mosasaurus in this environment with most specimens from this time being attributed to them of the trio the smallest was clases who was still by no means tiny with certain specimens growing up to 6. 2 M or 20 ft in length which is similar to the length of the largest recorded great whites although it was much more narrow which came with its own advantages as it allowed it to be an extremely agile Hunter he used it smooth teeth to catch a variety of fish and inverte Ates within the shallowest parts of the Seaway while it wasn't designed to be a threat to human-sized animals per se this Mosasaur was still capable of a nasty bite and may have even been able to travel for some time into fresh water making it that much harder to avoid things start to further ramp up on moving on to the platic carpus as this abundant Mosasaur was a tad bit bigger with certain individuals measuring 24 ft or 7 m from head to tail while weighing about 1 ton close to the weight of giant Nile Crocs after af's current largest Predator at this size the plat carpus should hopefully raise your thalassophobia more than clidastes and yet ironically it likely wasn't a huge threat to Aquatic megap since studies on its teeth have found them to have been extremely fragile leading paleontologist to speculate that it feasted primarily on smaller fish and soft tissued squid within deep Waters it might start looking like this was the worst place ever solely for Little Critters but don't relax too much as the third most common Mosasaur was a giant with an appetite to match and this is the Tylosaurus this Mosasaur was in most ways the same as others of its kind just everything about it was much bigger with adults being anywhere from 12 to 15. 8 M or 39 to 52 ft long fairly similar to the length of a humpback whale and making one of the largest mosasaurus across the entire planet and unlike the platic carpus Tylosaurus had teeth that were no joke with matured individuals possessing up to 32 teeth at any given point that were fairly similar to each other in nature being large thick recurved and finely serrated perfectly adapted for tearing through large animals and thanks to its size Tylosaurus could pretty much bully anything it wanted to in its environment playing the role of an apex predator and routinely hunted a wide range of animals that is reflected by its stomach contents as they have included the remains of plesiosaurs turtles Birds bony fish sharks and even other mosasaurus the Tylosaurus is believed to have mostly U ized ambushes during these hunts where it would strike unsuspecting prey at high speeds and possibly deploying a secret weapon as well it's snout this snout was quite unique to tyus source with it being proportionally very long and having all teeth situated further back meaning that the front was pure bone the tip of the snout was also fitted with a robustly built a knob that was backed by shock compression structures leading to the belief that this snout was literally a built-in Ram that Tylosaurus used to bash animals around and evidence shows that Tylosaurus was quite liberal with the use of this weapon being a hyper aggressive animal that attacked nearly everything including itself as adult specimens routinely bear damage thought to have come from other competitors even the rare yet equally deadly mosasaurus was sometimes attacked with one fatal case even being known of where in a Tylosaurus had rammed and smashed the brain case of a mosasaurus apart leading to a swift death don't get it twisted though as mosasaurus still held the distinction of the largest Mosasaur and therefore predator in these Waters occasionally growing to be 17.
1 M or 56 ft long and weighing over 10 tons and while it didn't have a battering ram like Tylosaurus did mososaurus arguably had the deadlier bite with its skull being relatively large for its body allowing for a row of giant teeth that were made for slicing and dicing each tooth possessed two opposite cutting edges as well as prisms that ran down the sides helping each bite to cut deeper while simultaneously improving the overall gripping strength its bite was also much more powerful with studies suggesting a bite force of between 13,000 and 16,000 lb per square inch which is four times the power of a saltwater Croc's bite with such power and size mosasaurus became another one of the western interior seaways apex predators having a dite just as diverse as the Tylosaurus and again similar to as relative it is thought to have employed Ambush hunting to capture prey unlike sharks these Giants didn't rely on a keen sense of smell to Target prey rather they had powerful binocular vision that provided pristine views in the mest of waters and unfortunately for all Tylosaurus and mosasaurus were not the only Giants of their kind prowling around with great vision as you also had mosasaurus like prognathodon which was only 25% smaller than the mosasaurus and also had a ferocious bite remarkably despite holding the title of the biggest predators the mosasaurus did not have the deadly Jaws in these Waters as that title went to a predator that coasted the most outer edges of the western interior Seaway the dino sucus yep that's right this prehistoric body of water not only had the largest mosasaurus of all time but one of the largest crocodilians as well currently scientists are not positive on the extent of the dinos sucus presence in the region but it's thought that it definitely inhabited Bays estuaries in the coast while perhaps venturing into deeper waters as well from time to time since specimens have been found in Marine deposits furthermore it definitely lived on both the eastern and western side of the Seaway and interestingly differed in size depending on which side it lived to the east dinos sucus grew to smaller sizes but were far more plentiful while in the west they were fewer but far larger reaching 12 M or 39 ft in length this obviously isn't very close to the length of the largest mosasaurs though dinos sucus was far more robust in build allowing it to stand its ground when it came to weight with estimates suggesting a Max maximum of around 8. 5 tons disregarding weight dinos sucus had the advantage of more impregnable defenses since like many crocodilians it too was covered in osteoderms however dinos sucus was a bit unique in that its osteoderms are much larger and heavier than normal in fact when they were first recovered paleontologist confused them for the armor of an enchilosa surus these homegrown armored plates would have covered the back of adult and were hemispherical in shape providing ample armor while also serving as a attachment points for tissue which ultimately played a massive role in its ability to walk outside of water overall these osteoderms made dinos sucus one of the better equipped animals in the waters but what really made it stick out was its monstrous bite for starters dinos sucus had massive skulls that were alligator like in structure meaning they were very broad giving them immense biting power that was only Amplified by the presence of well-developed jaw muscles all of this resulted in a bite that potentially delivered more power than even that of a fully grown t-rex with some studies estimating a bite force of over 100,000 Newtons five times the power needed to crush a car this staggering amount of energy would have been channeled into their robust teeth that were sharper towards the front and blunter towards the back suggesting that this Croc was designed to crush things to death rather than tear it's thought that like the American alligator dinos sucus was an opportunistic feeder who munched on anything it could catch yet fossil evidence shows that it had a preference for marine Turtles large fish and dinosaurs that ventured too close to the water the coasts and shallow reefs of this prehistoric Seaway were no doubt a terrible place to be if trying to avoid the largest Predators around but the more open Waters were home to their own share of nightmares too including rather peculiar seop pods to say the least Cretaceous spilop pods like those of today were still found in shallow water but they held a much more expansive range in the deeper areas compared to others despite not being as big big or as bad as the mosasaurs or dinos sucus for that matter they still feasted on whatever was floating around as Western interior Seaway spilop pods were among the biggest of their kind even rivaling the size of living Krakens today like the colossal and giant squid two of the better known large seapods from those times were tuso tus and anus both members of the now extinct enot family these two sea monsters were incredibly similar so much so in fact the paleontologists often like to argue on if a recovered specimen belongs to one or the other what we do know though is that they were big frightening looking and confusing confusing in the sense that they had the appearance of a girthy relatively short squid and yet were more related to Modern octopus than living squids in their youth these seapods were quite small and vulnerable to attacks with paleontologist believing that they actually made up the bulk of a lot of aquatic animals diets an idea backed by prehistoric fish stomach contents however in in response to being fish food these seop pods adapted by maturing rapidly and showing extreme size variation among individuals leading to some specimens being about the size of your arm While others could get 3 m or 10 ft long at this size these guys were active predators and turn the tables on their once wouldbe attackers typically eating fish invertebrates and even vertebrates like baby mosasaurus and Plesiosaurus akin to how octopus hunt tuso Tois and anko Tois would have used their 10 tentacles lined with suckers to an snare prey which were then swiftly ushered into their waiting beaks additionally while not confirmed many think that they were also capable of squirting ink when a Quick Escape was necessary and were quite Speedy relying upon jet propulsion to maneuver the waters obviously these seop pods had some useful tools yet one area that they were lacking in was armor as their bodies were for the most part composed of very soft tissue although there was another seop pod lurking around that had an answer to this problem this was parapuzosia despite hailing from the same class of animals parapuzosia was not an octopot like the two formerly mentioned creatures but instead a member of the ammonite order a now extinct group of spilop PODS whose closest living relatives are the colloids all members of this order parapuzosia included bore spiral shells which were made of calcium carbonate the same mineral scene in snail shells analysis on the shells showed that the calcium carbonate was arranged in prisms crystals or other shapes and patterns depending on the layer these shells provided a fair degree of protection against predators and also house the majority of their bodies which in the case of parapuzosia was a lot since it was a true sea monster holding the title of the largest known ammonite and the heaviest seop pod of all time outclassing both the Giant and colossal squid the largest known parapuzosia had shells that were possibly 3. 5 M or 11 ft in diameter meaning that with flesh these individuals are probably over 1.
5 tons in weight of which nearly half came from the shell alone and if you could somehow pry a shell off of one of these Giants it's thought that their body would uncurl to a total length of 60 ft or 18 M about twice the length of a whale shark such size gave parapuzosia one more Accolade the heaviest invertebrate of all time but what it did with his size is unknown as all members of its order and their closer relatives are extinct rendering their daily lives a mystery what we do know though is that individuals could be found throughout the entire Western interior Seaway intended to stick to the upper layer of water typically not going below 250 M or 800 ft meaning that unlike giant squids of today these behemoths weren't hard to find and finding it may not have been in your best interest either as it could have been Adept to catching fish other seop pods and even marine reptiles however on the flip side some think it was actually more likely to give you a death through jump scare than predation with some arguing that it mostly stuck to vegetation and pl only hunting the slowest of creatures due to its sluggishness it's quite shocking that this giant bizarre invertebrate could be found in an area that also house the largest Mosasaur and one of the largest crocodilians of all time making the Western interior Seaway seem like something out of a monster movie and at the very same time there were Horrors swimming around that we are all too familiar with including sharks they may not have been the true Kings of the time but they were still highly successful playing the role of both scavengers and active predator Predators while also being one of the most commonly found carnivores around like many these Cretaceous sharks apparently had a touch of gigantism as a few types found in the Seaway were among the largest known sharks although in contrast to say dinos sucus size didn't necessarily mean the sharks made the waters deadlier since the biggest of them all the tight cotus was actually relatively harmless to most this was a maal shark the size of a whale shark but unlike the whale shark didn't use filter feeding but yet was still highly specialized in its own regard sporting a durophagous diet meaning it primarily ate anything with a shell or exoskeleton this odd diet was deduced by the shark's teeth which weren't sharp or serrated but were instead fairly flat plates that were designed to crush these teeth were abundant sometimes numbering over 500 and could be absolutely huge with the biggest recorded being longer than a ruler these robust teeth would have allowed the shark to easily crush a variety of slow hard moving prey like Crustaceans or turtles not all sharks are this docile though as when you do go down in size you run into a still fairly big yet much more voracious toothy fish the cxy rhina more commonly known as the Ginsu shark like tyus this was a macal shark but this one bore a striking resemblance to our very own great white while also sharing an oddly similar lifestyle even though the two were not closely related demonstrating a case of convergent evolution millions of years in the making this was obviously ter terrible news for any animal around since it meant that the ctox AR would have taken a stab at any kind of prey if the size was right but it gets even scarier because this shark was particularly good at killing a certain kind of animal active Predators that's right the bulk of the ctox rina's diet came from other megap fonal Marine Predators such as sharks mosasaurs plesiosaurs and fish all of which have been found in the stomach regions of certain specimens such a diet indicates a hyper aggressive animal and brings up the the question of how it achieved such a feat well the secret lay in its size and Locomotion as despite sometimes being 8 m or 26 ft long and weighing over 5 tons it was still ridiculously fast evidenced by the pattern of its plaid scales which reduced drag and were organized in a fashion only seen in the fastest living sharks additionally cxy rhina had the most extreme case of a type four tail fin seen in any mackerel shark big news as this type of fin supports high speeds and models estimate that this giant could have topped speeds of 70 km or 43 mph where its powerful jaws would have then come into play dealing catastrophic damage as they were lined with rows of razor sharp teeth which were bigger than those even seen in great whites and also had thicker coats of enamel in order to survive these massive collisions fossil remains support the notion of high-speed attacks too as nearly all bones found with bite marks belonging to this shark are extremely deep and large and some of these s fossils have actually come from dinosaurs showcasing that not even the rulers of the Mesozoic were safe albeit the dinosaurs in question which were a hadrosaur and ankylosaur were likely scavenged after their corpse had been washed out to sea yet the cxy rhina is still more than enough shark to fill anyone's galeophobia but the fin nightmares didn't stop with it as you can't forget the presence of a smaller shark that still managed to make the waters even more quotequote interesting the squal korax better known by its nickname The Crow shark it's two is a mackerel shark however it was quite a bit smaller normally measuring between 1. 8 m or 5. 9 ft and 4.
8 M or 16 ft in length similar to the size of a tiger shark and its likeness to the tiger of the ocean went beyond its size as its teeth were remarkably similar too being numerous relatively small curved and serrated perfect for cutting and sawing through tough tissue with such deadly teeth the crow shark was capable of devouring many kinds of food that largely overlapped with the diet of the cxy rhina with the major difference being that it went for the smaller individuals another difference between the two was that the crow shark tended to stick to more coastal areas and supplemented a larger portion of its calorie intake with Scavenging which again partially consisted of dinosaurs it also developed a unique skill hunting the rulers of the sky in other words the terrasaurs since as opposed to other sharks the crow shark has been known on more than one occasion to have successfully attacked large terrasaurs namely the the Pteranodon which suggests that it had excellent Vision that it used to track parasaurs when they were getting ready to die for a fish and speaking of fish crow sharks are pretty good at hunting them too with many specimens containing large amounts of fish within their stomachs among the fish that have been found there is one that is really stuck out to paleontologists since it too is well known for being a famous sea monster of the western interior Seaway the Zac Tinus you may recognize this name from certain documentaries or you might more familiar with its colloquial name the xfish it was a large bony fish that belonged to the now extinct order known as the eodc forms who were specifically comprised of rayin Fish and were some of the meanest ugliest fish to ever arise with the xfish being no exception and probably holding the title as the meanest looking of the bunch the main feature behind its terrifying looks was clearly its mug which was broad pushed back and slanted and while this face xed any chance for a career in modeling it's what gave the xfish its fearsome reputation and status as a top predator as the jaw was highly flexible allowing it to virtually swallow anything small enough which meant a lot considering that adults could grow to be 5 to 6 M or 16 to 20 ft in length at the lower size estimate xfish were capable of swallowing humanized prey with one gulp as depicted by the fish within a fish specimen which showed a 1. 9 M or 6. 2 ft long fish that had been swallowed whole by medium-sized xfish furthermore there are over a dozen other specimens that show similar findings and on top of this crazy ability this fish could still also cut through things with ease thanks to their narrowed and sharp teeth allowing them to both scavenge large animals or cut up living ones that could then be swallowed in smaller pieces this was definitely the last non- shark fish you'd want to meet and with the xfish you'd also start to arrive at the end of the list of sea monsters that truly made this place hell's aquarium naturally though there were plenty of other pip ofor and carnivores that I didn't mention yet most didn't really make the Seaway stand out in terms of deadliness however you really can't forget that there was one more iconic group present the plesiosaurs these guys like the mosasaurs had four flippers but the similarities stopped here as Plesiosaurus had broad flat bodies and short weak Tails while their necks could also be comically long giving certain members the longest neck to body ratio of any reptile to swim they would have flapped their flippers in a flying ocean and mostly stuck to the shallower waters so far multiple kinds are known to have inhabited the Western interior Seaway with a bulk being plesiosaurs while a few species of poly cottids were present too some of them could get quite long and were typically over 15 ft or 5 m from head to tail with the longest having been the elasmosaurus and Alberto nectis both of whom grew to around 11.
