Giant Prehistoric Death Storks - Azhdarchids (Part 3)

welcome back to our series on as dark at pterosaurs so far we've looked at a few of the different giant species within this wonderful grouping and their research history as well as examining just how these incredible reptiles were able to take off into the skies now we're going to be looking at the various different lifestyles that have been proposed for these animals and see which of these is most likely to be the correct way to view how the pterosaurs lived throughout the extensive research that has been done on these organisms some very diverse and at times fairly ridiculous suggestions have been made for how they behaved this is perhaps not too surprising given how totally bizarre as dark it seemed to us with an oval Anatomy not quite like anything alive today so let's dive into some of these ideas one of the earliest suggestions for the lifestyles of these pterosaurs was made in the actual announcement of the discovery of Quetzalcoatlus possibly the most famous and the best known of all vias dockets published in 1975 the discovery of a giant flyer like this invited all sorts of questions into how such a remarkable creature would have fed and the ecological niche it would have filled well the first idea was the Quetzalcoatlus was specialized to be a scavenging animal flying around over great distances on the lookout for large dead dinosaurs it was thought that the long neck and beak of the pterosaur would have enabled it to probe deep inside the carcasses of big animals therefore living in a similar manner to our modern day vultures the evidence for this sort of behavior was explained to be the fact that the location where the first fossils of kwatak wallace were found was a non marine deposit far away from any large lake deposits and the only streams nearby were very small additionally the fossil remains of sauropod dinosaurs were known from nearby areas and therefore it was deduced that these animals could not have been piscivores instead they must have been adapted to feeding on carrion the long neck was also as I mentioned before thought to be a specialization for this however this isn't the best evidence for such a lifestyle just because the pterosaur was found in association with big dinosaurs doesn't really prove that they were scavenging on them indeed the scavenging hypothesis has been mostly abandoned by pterosaur researchers with it being argued that the beak was just not strong enough to be able to dig deep into caucuses and pull out bits of flesh unlike scavenging Birds today which have reinforced bone around the openings of the rostrum as Dockett skulls had relatively very thin bones surrounding these areas also it's been suggested that the bony crust on top of Quetzalcoatl is's head would have impeded its ability to probe into carcasses and additionally the very stiff necks of these animals would make this behavior difficult to perform so being specialized obligate scavengers doesn't seem to have a great deal of good support from the anatomy of these pterosaurs of course this isn't to say these animals would not have scavenged the occasional carcass if they had the opportunity but they were certainly not specialized for this and therefore would not have been doing it all the time so this brings us to another lifestyle that was later proposed instead of being scavengers it was suggested by other paleontologists that Quetzalcoatlus actually fed on invertebrates that burrowed into the soils or sands of the time utilizing their long and pointed beaks to poke into the substrate as they searched around the main evidence for this behavior though is again just the Quetzalcoatlus fossils had been found near by two other organisms but this time there were traces of invertebrate burrows current bird species that perform this behavior do so through the use of organs that detect pressure gradients and vibrations produced by that burrowing prey in addition to the sense of touch however there is no evidence and as Dockett skulls such as sensory pits that these prehistoric animals possessed the sorts of organs used for detecting prey items submerged in sediment other morphologies of the skull also don't really display the same features of mud probing birds that would make them specialized for this feeding method and the stiff elongated neck would again result in the pterosaurs having a difficult time performing the actions necessary to probe the substrate since its first suggestion the mud probing hypothesis has been quite significantly argued against by other researchers studying pterosaurs and even mocked in some cases leading to this idea to being mostly abandoned instead many of the paleontologists who rejected the mud probing lifestyle favoured a very different feeding technique which for a while became the generally most widely accepted and popular idea of how as dark it's lived this hypothesis proposes that these pterosaurs were skin feeding animals and would fly very close to the surface of a body of water using the stiff necks to dip their lower jaws down until they came across a prey item in the water at which point they quickly snapped their jaws shut and raised their beaks above the surface evidence for this sort of behavior first sighted as that this feeding strategy had been suggested in other pterosaur groupings and so therefore it was plausible that as dark-skinned fed - not the most airtight argument but later on other pterosaur researchers added some morphological evidence stating that the rostrum of Quetzalcoatlus was compressed from side to side and that these animals were not at all suited for walking about on the ground therefore they were adapted for feeding while flying above the water additionally the skull being streamlined and the elongated stiff neck was considered as support for this hypothesis unfortunately some of these descriptions of morphology are not entirely correct and there's actually quite a bit of evidence that's been argued by other paleontologists as going against the implied schema feeder lifestyle for example as Dockett skulls are not actually particularly streamlined or even compressed from side to side in the way that modern skimmers are the jaw joint and back of the skull were not well suited to enduring sudden impacts and the jaws would not have been capable of shutting very quickly this brings us to one of the most recent ideas for how as dockets lived but before we get to that let's quickly look at a couple of other proposals that are probably not as likely to be the true way these animals behaved one of these ideas suggests that as dockets were actually swimmers landing on the water's surface and diving down to catch aquatic prey similar to various different modern bird species as well as to what has been suggested for other pterosaur groups however the body plans of as darka pterosaurs would seem to inhibit this possibility seeing as there are no adaptations of the limbs for a swimming action the feet are relatively very small and so would not have been useful in underwater propulsion and their broad wings large heads and positioning of the skulls at the end of their long necks doesn't appear to result in a particularly streamlined anatomy for effective movement through water additionally any sort of specialization for sitting on top of the water can be ruled out as researchers have recognized that when Birds float on the water's surface they will tend to hold their heads near or directly above the center of buoyancy however as dark it would have been incapable of orienting their stiff necks and large heads into high angled positions meaning they'd be very unstable if they were to land on water another suggestion that hasn't really had much support from pterosaur researchers is the idea of as dark it's being midair predators that caught and fed on smaller flying animals this doesn't fit well with the morphology of these animals for a few reasons especially since aerial predators would have to be very agile while flying which giant as dark it's certainly were not as well as this these reptiles would have been forced to capture prey midair using their jaws not their limbs since this would destabilize them and result in the wing being stalled however the jaws of these animals are nothing like what we would expect for an aerial predator making this another very improbable mode of life for these pterosaurs so this brings us finally to what currently appears to be the most likely way as dark it's lived which has been mostly accepted by a lot of pterosaur researchers in more recent years this is the hypothesis that as Dawkins were stuck like in their lifestyle being generalists that opportunistically fed on animals they came across on land or in shallow water in other words they were giant prehistoric death storks there's a lot of good support for this idea with the morphology of the animals actually in agreement with such a way of life for example the pterosaurs were clearly very well-suited to walking about on the ground as can be determined from the foot anatomy and the length of their legs which would be necessary for a stalk like feeding method the stiff elongated neck and large skull which has presented issues in the other proposed hypotheses actually makes sense in the context of terrestrial foraging since it means only a limited amount of vertical movement in the neck and skull is needed with a small flexion of the neck easily bringing the lower jaw down towards the ground allowing food items to be picked up the skulls of as Dockett pterosaurs have also been described as resembling those of living birds that behave in this way stalking about terrestrial environments examples of ground hornbills marabou storks as well as Jabiru storks have been given with long but fairly deep beaks similar to those seen in the pterosaurs though the generalized psycho Nia stork genus is cited as the best modern analogue to these creatures this generalist morphology means that the as Dawkins could have been feeding on a wide variety of different food types which would be crucial if they were wandering around on the lookout for anything they could eat significantly the generalization of the skull also means that they lacked any of the specializations that would be needed for the lifestyles of skimming scavenging mud probing or aerial predation although certain as Dockett species do seem to have specialized into variations of the terrestrial stalker mode of life for example hatsue copter x being particularly robust and with a relatively shorter neck becoming the top predator of this ecosystem and Elan qua which potentially had a jaw suited to crushing hard foods such as shellfish and there may actually be some support from trace fossil evidence for this hypothesis - there's a trackway known from late cretaceous rocks in mexico preserving what have been interpreted as dark 't hind and fore feet traces as well as some strange gouges these gouges have been suggested by some to perhaps be scrapes caused by the beak of the animal that made the other imprints meaning that this might be direct fossil evidence that as dockets could indeed lower their jaws all the way to the ground however after this hypothesis was first proposed by paleontologists darren naish and Marc Whitten back in 2008 it did receive some criticisms specifically in a 2013 paper which argued that fossils of as dockets are very often found in aquatic deposits so they must have been feeding their that as dog heads being on the ground would have made them incredibly vulnerable to predators and that a pelican like feeding method is much more likely but a response to this was soon published defending the terrestrial stalker hypothesis are still the most probable interpretation we have of as dogged lifestyle the first criticism that as dark-eyed fossils are found in aquatic deposits is a pretty weak argument given that fossils of terrestrial animals are often found in such deposits since this is one of the best places for fossilization to occur indeed these pterosaurs have often been discovered in the same aquatic deposits where reptiles such as dinosaurs and birds are found because this is just where they all end up after death the next problem was the suggestion that as dockets would have been highly vulnerable to attack from predators if they were walking around on the ground a lot of the time but this is also not the best argument especially since such an assumption is pretty speculative modern bird species that practice the same sort of lifestyle don't seem to be constantly under attack from predatory animals meaning it is possible to live in this way without being instantly torn to shreds and although today's terrestrial stalkers are not living at the same time as huge theropods these animals are not likely to have been a constant threats to giant pterosaurs probably prefer to go after much easier to catch prey like modern predators do as we saw in the last episode large as dockets were quite proficient are quickly taking off using the quad launch method and therefore would also have been able to avoid potential dangers if they needed to it's also worth acknowledging there's a giraffe sized creature with a massive shop beak on its face would have been a pretty terrifying thing to see and making one angry could end quite badly for the aggressor finally the ultimate suggestion of a pelican like feeding strategy is also not really more likely than the terrestrial stalker idea this proposes that the pterosaurs flew close above the water's surface like with the skim feeding hypothesis and then opened their jaws when they saw prey expanding out a throat sac to swallow the organisms but as Witten and nature explained there are many issues with this idea as dogged jaws lack all of the very unique specializations present in Pelican jaws that allow them to feed in the way they do and the bit of anatomy and has dogged skulls cited as the main evidence for such a feeding technique a helical jaw joint which supposedly allowed the lower jaws to bow out and expand the volume of the mouth like a pelicans is actually present across many different members of the arcus or lineage in animals the feed in a wide variety of different ways meaning it's not likely this feature has much significance in how an organism feeds once again it was found that the morphological evidence best suits a terrestrial stalker mode of life for us dockets and this now seems to be the most accepted as docket lifestyle though keep in mind that new discoveries could always change our perceptions of these animals but for the moments this is the most probable hypothesis we have the whole journey of scientific discovery seen in the history of as dogged research is a really fascinating example of how science can work despite the several instances of not exactly great science going on with assumptions about lifestyles being made from a few selective examples of anatomy nevertheless after a while a more evidence led objective overview of the whole Anatomy came along that presented a logical interpretation of how these ancient organisms could have lived and what an incredible group of animals for this to all be focused on new discoveries about as dockets continue to be made and hopefully we'll see many more developments in our understanding about these creatures in the future I really hope you all enjoyed this series on the other kids and I'm sure will end up revisiting these utterly amazing organisms again in more videos they're just too cool to leave alone before we end this video I'd like to again recommend checking out the sources I've used particularly Mark Weddings brilliant blog posts and his great book on pterosaurs which should be a standard for anyone interested in these animals or even paleontology and evolution in general and thank you to everyone who sent in their wonderful artwork it always amazes me to see the incredible artistic talent people have we've had a lot of art sent to us so I apologize if you're not featured yet but we're going to keep this going every week so we can hopefully feature as many people as possible anyway thank you so much for watching this video I really hope you enjoyed it and learned something new if you would like to find out more about our world its history and the wonderful life that surrounds us all please feel free to subscribe to the channel if you think we deserve it and if you would like to see more from us [Music] [Music]

Channel: Ben G Thomas

Views: 191,710

Rating: 4.9537024 out of 5

Keywords: Biology, Science, Paleontology, Palaeontology, Dinosaurs, Animals, Nature, Wildlife, Ben, Thomas, Prehistory, Anatomy, Fossil, Bones, News, 7Daysofscience, Days, of, pterosaur, quetzalcoatlus, hatzegopteryx, arambourgiania, alanqa

Id: r4WAt68j6n0

Length: 14min 26sec (866 seconds)

Published: Sun Sep 01 2019