When Giant Scorpions Swarmed the Seas

When Giant Scorpions Swarmed the Seas

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Language: English

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we'd like to thank audible for supporting PBS some 400 million years ago in the early devonian period the world was a very different place sea levels were high and the continents were surrounded by vast shallow seas full of exotic creatures like rugose corals crinoids and jawless fish and in what's now Utah one such fish met an inn that was as grim as it was typical the jawless fish known as Lake Erie aspis was killed by three distinct puncture wounds to the head puncture wounds made by crushing claws the culprit was an
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apex predator that dominated the Seas of the late silurian and early devonian the sea scorpion sea scorpions thrive for 200 million years and they came in a wide variety of shapes and sizes from alcone op tourists which was about the size of a paperclip to the terrifying ye calop tourists which was two and a half meters long but in time these able hunters would meet some stiff competition in the late devonian giant armored jawed fish the plaka derms would come to dominate these seas and force other ocean dwellers to adapt flee or
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perish these formidable predators would give the period its nickname the age of fish and as a result of this competition sea scorpions would eventually diverge into two distinct lineages each with its own unique strategy for dealing with the rise of fish they developed a number of adaptations from those crushing claws that snagged the unlucky Licari aspis to the flattened tails for swimming as well as primitive lungs and strange filter feeding appendages and some of them adapted by getting so big that they still hold the record for the largest
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arthropods of all time they would even make the giant historic leap from the water onto dry land but unlike their other arthropod relatives that we share the world with today for the sea scorpions that move would prove to be the beginning of the end [Music] scientists know sea scorpions by their proper more accurate but also somewhat less cool name you ripped rids any rep dreads probably aren't ancestral to the arachnids we know as scorpions today sea scorpions and true scorpions are
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actually sister clades that both belong to a subphylum known as kala Sarada an ancient group of arthropods that first appeared in the oceans of the Cambrian period by the time a Silurian period rolled around tens of millions of years later the two clades had diverged each adapting a different way of breathing that ultimately set them down very different evolutionary paths in the lineage of true scorpions external respiration organs called booked gills were adapted into internal booked lungs these long has allowed the ancestors of today's arachnids to become some of the
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first animals ever to colonize land sea scorpions meanwhile retained their book gills which are similar to what horseshoe crabs used to breathe today and this kept them dependent on water mostly but they also developed a second respiratory system known as a caiman patan which functioned as a rudimentary lung and allowed them to take short trips onto land because of these features some researchers believe that caimen patan allowed sea scorpions to mate and lay their eggs on land or even develop an amphibious lifestyle but as
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history would show this adaptation would prove to be a limitation as well as an advantage in 2015 the earliest known europe turret Pinta copter is Dec hora hence as' was discovered in rocks in Iowa that date back 467 million years it had compound eyes a two section body and six pairs of appendages the first pair by the mouth would have been used for feeding while the other five were used for moving around sea scorpions would soon come to be defined by how these appendages adapted splitting off into
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two distinct sub orders with two very different evolutionary strategies the first sub order to appear was stylin Ariha and its first known member breaky op tourists showed up just nine million years after Pinta cop tourist in what's now Wales this species was a humble little water monster just under 20 centimetres long and it scuttled along on ten legs scavenging for food at the bottom of the shallow these like all of the stylin Aryans that would follow breaky op turists used its appendages for walking and stuck to a strategy of scavenging and filter
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feeding on the sea floor in order to stay out of the way of fish which were on the rise but during the late Ordovician a second sub order of sea scorpion emerges in the fossil record the Europe terena the earliest known Europe terrine is a little species dated to 445 million years ago discovered in the shales of South Africa and these sea scorpions had a pair of appendages that were more like paddles which allowed them to swim a lifestyle that put them in direct competition with jawless fish and cephalopods the newfound mobility of this group allowed it to diversify
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throughout the Silurian and fast as they were able to colonize new areas and take advantage of new niches plus by competing with fish and cephalopods they put themselves under selective pressure and launched an evolutionary arms race with other swimmers this led to much greater diversity in this sub order which is probably why 75% of all known Europe turrets species and more than 95% of all specimens ever found belong to Europe dureena but as the fluorine gave way to the Devonian a dangerous new competitive pressure entered the seas the armored
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jawed fish known as the plaka derms so after reaching their peak diversity at the very start of the Devonian period the number of europe tureen species begins to drop in the fossil record likely because many simply couldn't compete with this newer powerhouse predator but the e-rep terrines that did survive managed to stage a sort of evolutionary rally getting bigger faster and stronger in the Devonian to cope with seas filled with placa derms that were doing the same so we probably have placa derms to thank for the nightmare fuel that followed a family of giant
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europe terrines that persisted for nearly 40 million years these are known as the Terra goatees they were some of the only sea scorpions to cross the open ocean exploring the seas between the continents of your America and Gondwana and several aspects of their Anatomy indicate that they were active powerful predators they had thin lightweight exoskeletons that helped them move faster and flattened tails called Tulsans that gave them extra swimming power their eyes faced forward and had thousands of Lin giving them keen eyesight for spotting
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prey and they caught that prey with mouth appendages called kulasara that ended in large Raptor like claws these claws were so robust that they often preserve better than the thin exoskeleton and sometimes they're the only parts that remain in the fossils of tear goat its many tera goat heads reached over 1 meter in length but the king of them all was Yi Kalakh Duras the largest arthropod that has ever lived maxing out at 2 and 1/2 meters long it was described from a cloth found in Germany in 2007 that's nearly a half metre long with tooth like serrations
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that were about the size of a tigers canine teeth but despite their best efforts these invertebrates couldn't keep up with the plaka domes and europe terrines lost over 50% of their diversity within the first 10 million years of the Devonian by the end of the Devonian all of the giant marine europe terrines had gone extinct only one swimming genus the tiny and widely dispersed adela fathima's remained but while the dramatic rise and fall of the erupted arena had been happening out at sea the slow and steady style an area were still hanging on in contrast to
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their cousins the europe terrines the stylin Aryans remained relatively unaffected by the rise of fish while the Europe terrines were busy competing with fish stylin Aryans moved inland to brackish and freshwater ecosystems where there were fewer placa derms and less competition by the time of the Carboniferous period about 360 million years ago Gondwana and euramerica had come together allowing the styling durians to spread out over the new supercontinent now the Carboniferous is most famous for giant arthropods like the 2 meter long millipedes and the
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Griffin flies with wings bands larger than that of some birds but if you were to hang around the muddy banks of a river you might just spot the last of the giant sea scorpions a big weirdo called Hibbert up drous this was a very different sort of creature from the swimming predators that had come before it was basically a big tank like rumba slowly combing the sediment at the bottoms and the banks of swamps and rivers with spiny sweep feeding appendages a big track we discovered in Carboniferous rock in Scotland has been attributed to Hibbert och
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and these tracks suggest that while it wasn't as long as you cooperate it was probably heavier with thicker legs to support it on land scientists don't really know why Hibbert top tourists got so big but the size increase was gradual indicating that it might have been to better adapt to the species new fresh water home that's because Calissa roots have blood that has a salinity similar to that of seawater so a larger body size and thicker exoskeleton would have helped insulate hobart top tourists to maintain its blood salinity in freshwater and
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even in the open air however top tourists died out in the Carboniferous but other hipper top turrets persisted for millions of years the final year if trade can't be low cephalus permi anis disappeared at the end of the Permian period during the biggest extinction event in Earth's history the in Permian extinction event also called the Great dying was probably triggered by massive volcanic eruptions in Siberia that warmed the climate and killed off more than 96 percent of marine species and 70 percent of species on land Campolo cephalus was among the many casualties
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and with its demise the 210 million year age of Europe Therese was brought to an end while sea scorpions ultimately succumbed to the evolutionary pressures of powerful new vertebrates and mass extinction events for a big window of time they were the most fearsome and diverse arthropods around and they show us how different evolutionary paths can have very different outcomes by laying low and avoiding competition style owner Ian's stuck around millions of years longer while your rip terrines were far more diverse and plentiful at their peak
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in the end their undoing might have been their inability to fully colonize the next frontier dry land where there was less competition and many more niches to fill while the sea scorpions couldn't make the transition it was made successfully by the Europe turds sister group the arachnids maybe if they developed a way to leave the water sooner if sea scorpions would still be around today just three classes of cola' Sarada remain on land there are the arachnids like spiders ticks and true scorpions and in the seas there are the sea spiders in the primordial looking
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horseshoe crabs living reminders of the watery origin of the coolest in the rain of the sea scorpions we'd like to thank audible for supporting PBS audible selection of audiobooks includes audible originals audio titles created by storytellers from around the literary world for example the genius dialogues an interview series where host Bob Garfield has conversations with individuals who have been awarded the MacArthur Foundation genius great visit
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