When you go swimming in the ocean or seas, the last thing you want to swim into is a shark... but wh...
Video Transcript:
if you walk up to your crush and Point Blank ask them who are the top dogs in the oceans and seas best bet is they're going to say sharks yeah we have things like orcas barracudas giant squids Etc but most people still think the salty Waters of Earth are ran by Jaws however at the same time in the grand scheme of life sharks claim to be king is a relatively new one as they only became prominent Marine Hunters following the end of the mesic which saw the extinction of the previous nightmares like the mosasaurs and pl what's strange though and unbeknownst the most is that sharks actually already had their chance hundreds of millions of years ago before the mesic and were actually doing better than they are now representing in many ways their true forgotten golden age as nearly everything swimming around back then was Jaws and this was the Carboniferous period to arrive at this point in history you would have had to travel back a mind numbingly long time as it played out between 358 and 298 million years ago in other words nearly 66 million years before the dinosaurs had even evolved ironically though despite it having been the best times for sharks these days it is better known for its variety of giant insects arthropods and amphibians that lived within the vast coal swamps of the time which stretched across the entirety Pangia a bygone ancient supercontinent now but a newborn baby back then as it formed during the very early days of the Carboniferous uniting the majority of Earth's land and covering up to 1/3 of the entire world which just in comparison the largest continent of today Asia Only scratches 8% and this is impressive at all but it's nothing compared what was happening to the waters because as the continents came ever closer to one another it resulted in huge amounts of undisturbed ocean and leading to the creation of super oceans which are unheard of today the big one was the panthalassic which lay to the East and occupied over half of the Earth's total area meaning that if you wanted to fly across it in a commercial jet you'd have to pack fuel for a Tri over 24 hours long and its size was so Monumental that it was pretty much the only freestanding body of water on the planet as the other ocean the paleotethys was in some ways contained by land and various Islands but it was still very much big by current standards and both oceans on vastness alone would give any sane person a very healthy dose of thalassophobia however our fear of water ultimately boils down to what's inside it and during the Carboniferous nature seemed to be injecting oceans with some sort of potion turning everything into sharks and if you went for a swim you'd have a better chance of swimming into something that looked like Jaws than not as sharks were painfully everywhere in fact so far paleont toos have identified over 45 families from the Carboniferous period while nowadays there's only a possible maximum of around 30 so an increase of nearly 35% but this difference is only really crazy when you take into account that oceans and seas back then were way more empty than they they are today as one study found that in the present there are about 800 or so different Marine families while back then there was less than 500 therefore sharks nowadays count for less than 4% of all Marine families but during the Carboniferous they made up over 10% a better way to imagine how insane this is is that if you wanted to make today as shark friendly as the Carboniferous was you'd basically need to double the amount of sharks swimming around which if you ask me is uh way too much what's more odd about this whole thing is that nothing else in the water was really popping off like sharks but on land there were multiple groups that were doing strangely well including those giant bugs and arthropods that tickle another fear in our brains and yet the coinciding time of giant creepy crawlies and shark NATO was in the end a coincidence as the former are believed to have Arisen thanks to an increase in atmospheric oxygen while the success of sharks is thought to have come from a completely different thing which was essentially luck just like many animals had done before them and would do after it turns out that they had essentially won Nature's equivalent of the lottery having survived a mass extinction with relatively little damage and this event that I'm referring to is the late devonian die off the second of the big five which killed roughly 50% of all jera at the time thoughts on what caused this event rang from severe volcanism all the way to the expansion of plants but whatever the case the oceans were especially rattled and many of the top apex predators were completely wiped out including the the placoderms who had ruled Supreme and nearly all of the sea scorpions and thus opening the door wide open for sharks who wasted no time and they were actually already pretty ancient at this point having evolved 90 million years prior but you could say that they were never really the popular kids but this time things would be different with a number of species ballooning by 350% in very little time and turning the world into an absolute sharkfest this included entirely new groups and new and improved versions of or existing ones many became bigger than ever before making sharks the largest animals swimming around While others push the limits on biological weirdness but one fresh-faced group that beautifully combined the two of these was the Eugenio Dona in now extinct order the first appeared during the seric covian stage scientists have identified 32 different Genera belonging to this group and they were largely United by two things one pectoral fins that were supported by long radials and more notably tooth WLS which were usually razor sharp serated teeth embedded into a spiral root which made them look pretty metal these a dental structures came in many shapes and forms but typically they had a strange resemblance to man-made saws with some bearing mouth similar to chains saws While others had what seemed to be built-in Buzz saws these bizarre Contraptions ultimately proved extremely versatile and the Eugenio deds rapidly became the dominant Hunters during the Carboniferous being found in both deep and shallow Waters where a few also became the Giants of their time most notable among the behemoths was the adest which is lovingly nicknamed the scissor tooth shark and it inhabited the UK Russia and the United States where it routinely grew to lengths greater than 6. 7 M or 22 ft so about the same size as the biggest known great whites because of the stature its two thels were absolute giant with each one being about the length of your arm and leading to great interest on how they were actually used for a long time the popular thought was that like its nickname suggests edestus would operate its mouth in a scissor-like fashion using cutting motions to chop and dice up unlucky prey with some reconstructions finding that each snip generated 1900 Newtons of force three times the power of a wolf bite however recently a new hypothesis paints an equally Grim but different picture where instead of moving its mouth edestus and its kin would instead move its body up and down in order to generate sawing motions and essentially thrashing prey into pieces and so both of these options either being snipped or sawed into pieces are not very fun and recently the list of potential victims have grown as well paleontologists used to think that it soliat jellyfish or maybe shelled animals but now we think it was more versatile praying on the previously believed animals as well as fish and other sharks and it wasn't the only one doing this as aestus was a part of the specific Eugenio daed family adest which included close relatives like helic campus lrus UK tenius and protop parata who all had similar dentition yet different in size with its relatives being more comparable to reef sharks than large great whites they were no doubt an odd Bunch but they really weren't the weirdest Carboniferous sharks with a better candidate being another Eugenio datia family the helicoprion this name may sound familiar for it was coined after the helicoprion a large Shar who had a circular saw for a bottom mouth while its top jaw were all gums a common theme amongst his family however despite being relayed to adustus and other Carboniferous Eugenio Don this Behemoth wasn't actually a part of the golden age of sharks living further down the line during the peran with instead the Carboniferous Genera from this family consisting of the azidus toxo prion and AR pagus all of who are sadly poorly understood and are not conclusively thought to be anywhere near the size of helicoprion don't you worry though because there was one more member that I haven't mentioned that wasn't just bigger than the helicoprion and adustus but is also the largest animal we know of to have ever lived up until the Carboniferous the Campo pron superficially it probably looked a lot like any of its close relatives but if you swam up to it there was no mistaking it for the Campo pron was massive compared to its coexisting kin with the largest known teeth suggesting a length of 9 M or 30 ft so basically on par with whale sharks from a length perspective to avoid such a monster you'd have wanted to steer clear from water surrounding Russia and the US where it was the Undisputed apex predator but who it terrorized is up to debate since like the adustus we haven't quite figured out how the helicoprion day used their mouths originally it was thought that they were designed to snag soft bodied prey like squid and Jellyfish which were then ushered down their throats as they closed their mouth yet now based on recent research there are some new possibilities one being that they were actually specialized in sheld seop pods as certain models found that if their whls contacted a hard shelled animal head on then a deshelling effect would actually take place when it retracted its whls and thus removing the soft animal hiding within separately another test that extrapolated bite forces of kin found that it might have bit with 2,300 Newtons of force while generating stresses G than 50,000 lb per square in which would imply that it was a lot more bloodthirsty than expected as such power would allow it to cut straight through bony fish and sharks without even the need for top teeth and we know this design definitely did the trick because not only did it remain present in peran descendants but it was also the route taken by two other main families that made up the Eugenio Dona those being the Casio dtoa and Eugenio Dante who opted for the same circular design over the type seen in adustus with the only major difference having been they're smaller sizes and instead of sharp serrated teeth they bore round pavement like dentition which indicated a durophagous diet of crushing sheld and exoskeleton bearing animals they also made up for their lack of size with weirdness because a couple like ornitho prion evolved some pretty strange heads on top of their whs which included a comically elongated bottom lip or rather Rostrum which jutted out like a spear and May been used to sift and prod the seafloor unsticking B valves and other floor dwelling prey like the others within this order these two families could be found worldwide and as a whole the Eugenio Dona were the face for carbon inferus sharks having played Major roles in many of Earth's Marine systems and yet despite their occasional giant size and terrifying appearances swimming into one of them wasn't always the worst thing because when sharks are at their best you're bound to get a couple of groups that are even more voracious with one of these groups having been the tenac caniforms superficially they mimicked modern sharks more than the Eugenio daed did that they were still a little bit off for one instead of having reduced second Dorsal fins theirs were large and in some cases even bigger than the first ones this may have helped cut down on drag though it could have also been a secondary adaptation to support another strange feature built in spines while Eugenio daed wanted to be chainsaws these guys wanted to be cactuses as members had large spines that connected to the front of their Dorsal fins and due to their size sharpness and occasional Thorns it's likely that they were used as a deterrent against other Predators including themselves as they could be quite feisty many of them lived in Shallow Waters where they would act as Ambush predators and held similar ecologies to the modern-day bullshark as well as falling within a similar body size range with the most common one the Drco prises having an estimated length of 2 m or 6. 7 ft while the rest nearly never made it past 2.
4 M or 8 ft although at that size it's not exactly reassuring the only Silver Lining here for the time traveling Enthusiast is that their diets were largely dictated by what could be swallowed whole or crushed as they possessed multicusp teeth a bit like those seen in Sand Sharks which were designed to penetrate prey and grip them tightly so they could then be swallowed rather than for slicing and dicing their prey to shreds therefore while fight would still probably suck especially since they had 12 rows of teeth megap most likely did not have to worry about getting gobbled whole this safety though was not extended to deeper waters as it was in the open ocean that the two largest tacan forms ever resided the glyc Manus and cidus these two were essentially the closest thing you had to great whites at the time in the sense that virtually everything at some point could fit in their mouths as adults could grow to be 7 m or 23 ft long and we close to 3 tons an exceptionally large individuals might have been even bigger with a set of abnormally large teeth from a cotus specimen indicating a length greater than 8. 5 M or 28 ft and despite the teeth not being designed for cutting they were on average longer than those seen in great Dwights so even if one just grabbed you with its mouth and then let go it' still be kind of like getting stabbed by hundreds and hundreds of mini daggers I mean just imagine a sand tiger shark's mouth but over twice the size it also didn't help that these two giants lived together at the exact same time and coexisted with a giant helicoprion as well leading to an abundance of Titanic sharks it wasn't that being big was necessarily a trend but rather that since sharks were so number there was bound to be a few who became massive but no others approached this chunkiness to this great of a degree remarkably though they did get weirder with the most perplexing having all come from the same order this simp Mor reforms families within this order were generally defined based off of specific internal anatomy meaning that some could appear quite normal in the outside like Clos sakade but others not so much with a couple developing some seriously messed up Dorsal fins with the chief perpetrator among them having been the steth canid I don't even have to explain what's wrong here as their Dorsal fins painfully resembled anvils more than actual fins and you may be wondering why on Earth would anything swimming when such a clunky structure strapped to its back and this is a good question has it likely caused a bunch of drag rendering steth canids slow cumbersome creatures that were most likely restricted to living on the seafloor endlessly looking for even slower prey to make matters worse they also had giant patches of many spines on top of these fins and their heads as well adding just more additional drag and making them wide open to attacks so why bother with these fins and spikes at all well based on recover specimens paleontologist concluded that only males possess these strange structures leading to the belief that these were used for mating displays amazingly enough they somehow managed to be slowed down even more thanks to quill like perturbances attached to their pectoral fins that stuck out backwards and yet in despite of it all they managed to exist for 50 million years and fossils have been found in the majority of continents with only Antarctica Africa and South America lacking any so evidently the fins worked you also can't forget about the falca either a Clos related family who had questionable Dorsal fins as well yet to a lesser degree as theirs were narrower and lighter allowing them to retain some degree of nimbleness of the four confirmed jera the only one we have a fair understanding of is the falcatus a tiny shark who is shorter than a ruler and who like the Ste the canids only had its modified fins on males leading to the same belief on its functionality and in another Act of solidarity falcatus and its relatives live deep underwater too but this wasn't out of necessity due to slow speed but rather due to the fact they had large goofy eyes that were specialized to pinpoint small prey zipping around in the dark depths of the ocean and they were actually surprisingly fast thanks to proportionately large and long tails which would have provided powerful Locomotion interestingly enough they and Ste the canids were equipped with cusped conical teeth just like the tacan forms were which was may be a good thing for those with philophobia but you did have other sharks to bridge this Gap and actually there was an entire order known for being the Jack of all trades when it came to dentition the hibdons swimming into one of them would be a hard thing to avoid and would kind of be like playing Russian roulette as each one had varying teeth they resulted in this group expanding to every kind of Niche possible and across the board members were capable of crushing tearing grasping or cutting through their prey they were further upgraded by having relatively robust bodies that allow them to Stage powerful strikes and emerge unharmed from intense battles and while not humongous some were respectively big measuring 3 m or 9. 8 ft long and in spite of each having very different teeth and therefore different prey there is a consensus that in general hibdons were slow swimmers and would use burst of speeds to chase down their unsuspecting prey and this group would only get stronger and stronger over time enjoying more success during the Mesozoic than during the actual golden age of sharks however there was one place where they were kicking butt and it was somewhere the Sharks had only managed to just infiltrate during this period fresh water and what this means is that no matter what body of water you were in there was a fair chance that a shark or two were just waiting within and to make matters worse back then freshwat was comparatively way more shark friendly than now hibdons were at the Forefront of this conquest and egg cases belonging to them have been found in many freshwater environments and spread out across the entirety of Pangia and in greater numbers than what was seen in the ocean the only saving grace here is that non-marine hibdons weren't that big with the largest genus the litus only growing to 2 or 0.
6 M and now that's the good news the bad news is that there was one other order of sharks that made freshwater environment their home and did the term River Monsters better Justice the xenics Keeping Up With The Times They were found everywhere and were highly aggressive Predators who are a lot bigger than our freshwater hibdons with the most well-known genus the xenacanthus measuring 1. 2 M or 4 ft long and that was one of the smaller ones however in this group The tinier jera were given additional help as similar to the tenan forms jera sported large spines or spikes that might have doubled as defense mechanisms against larger Xena cans and giant fish like the rise of on and its pointy end was possibly much more problematic than you'd assume as a few researchers speculate that they were venomous and even if they weren't stepping on one was guaranteed to suck as some grew to be 15% of the total body length ironically enough though xenics lacking massive spines were the true ones to fear perhaps because they didn't need them best exemplified by LEC acanthis the apex predator of late Carboniferous Rivers this zenan made Xena canthus look like a puppy as matured individuals were able to reach 3.