Why Were Triassic Animals so Weird?

[Music] so last week we explored the absolutely bizarre animals that existed during the triassic period i talked about some of my favorites or the ones that stood out to me for one reason or another but as i researched this topic one question started to come up time and again why were these animals so strange what was it about this time in particular that led to so many wild designs in nature but before i get into that topic i want to start by giving a little bit of an explanation to a question i got several times in response to my last video so what exactly is an archosaur archosaurs are a clade of reptiles that first evolved during the late permian as we've discussed they diversified into many different groups during the triassic groups like crocodilians pterosaurs and dinosaurs and by proxy birds are the most well-known members of this clade but during this 50 million year heyday they literally took over the world and although some of the different triassic success stories weren't actually members of the archosaurs like our long neck boy tennie strophius and the reptilian platypus drapanosaurus but in general these were all branches of the reptile family tree and the simplest way i can put it is that today when people think of reptiles we think of lizards snakes turtles and crocodilians well during the triassic there were many other kinds of reptile that didn't fit into any of these boxes because even if i try to make comparisons to living animals the fact is this is not like anything alive today and while we're on the subject of tanis trophy is i would like to make a correction to what i said about the noodle lizard last week i said that there was almost no chance that this animal lived in an open marine environment because of its small limbs that would not have been very useful for swimming this however is no longer thought to have been the case now as i said this animal is no stranger to being the subject of scientific debate i seriously feel like i could make an entire video just about the different ways that we've perceived this animal over the years but the most recent analysis comes from a digital reconstruction done of the skull that shows that the nostrils were positioned on top of the skull this along with learning that the teeth were interlocking in the front like many other animals that survive on a diet of fish and finding fossils that suggest that it may have been able to use its hind limbs kind of similar to a frog have led many to conclude that this animal probably did live in the water most of the time though still capable of getting around on land it's now believed that tannie strophius was probably a shallow water predator i want to thank tracy ford for providing me with the picture of what this creature's skull probably looked like in life but now with that out of the way it's time for us to tackle the bigger question and to do that i think the best thing to do is start at the beginning one thing to remember about the history of life on earth is that there are three major eras that multicellular life has existed and the first two have been punctuated by world ending catastrophes the most famous of these was 66 million years ago when a meteor struck the yucatan peninsula the results of this impact was the complete decimation of nearly every marine and terrestrial ecosystem and the extinction of roughly 76 of all of earth's species now this is the most famous extinction for two reasons for one it's the extinction that ended the age of the non-avian dinosaurs and for two it's the extinction that gave us and the rest of the mammals the opportunity we were looking for mammals did exist throughout the mesozoic but like the early dinosaurs in the triassic we were unable to become the dominant life forms on the planet until the old masters got out of the way but despite how well known this extinction is it was definitely not the worst thing to ever happen to life on earth if you go back to the earliest days of the triassic you would see a wounded world on the brink of total collapse the permian mass extinction wiped out literally 90 of the life on earth this would be the closest earth would ever come to becoming a dead world but luckily a few species did survive this great dying it was from this handful of survivors that would spawn the triassic freak show you see pretty much every dominant niche from the permian was left vacant because literally every single animal filling those roles was now extinct and as i've said all the way back in my very first video and probably several times since then when an ecosystem stays the same for a long time the specialists tend to do well thus they keep becoming more specialized to whatever it is that they were doing so they can remain on top but when conditions change they often struggle to roll with the punches and adapt now the details of this extinction are an interesting topic in itself and i have to really struggle not to go off on a tangent about it and make this video over an hour long which i wouldn't mind doing but then i definitely couldn't get it out to you guys by friday so today we need to focus on the 10 that did survive the permian extinction because whenever there's a lot of open niches caused by mass extinctions there is kind of a power vacuum where animals seem to quickly evolve to fill those roles and gain dominance this can lead to evolution taking designs in very interesting directions for instance a group of monitor lizard-like archosaurs evolving a disproportionately large head and with it comes a stronger bite force and a coveted spot as an apex predator this process is called adaptive radiation and with 90 percent of the life removed it didn't take long for the survivors to start evolving into all sorts of weird and wonderful forms until the biodiversity had built back up to a healthy amount this was sped up even more by the fact that the climate of the triassic was much more well suited to cold-blooded animals so basically from the ashes of the great dying the stage was set perfectly for the reptiles to take over the world and simply by taking advantage of it they inevitably diversified into all sorts of bizarre animals so as life recovered from the permian extinction the reptiles evolved into many different groups that were progressively getting more and more out there this is when we started seeing things like draponosaurus and hyperodapadon along with another branch of the archosaur family tree that remained pretty small until the very tail end of the period there were mostly generalist carnivores and omnivores with an upright bipedal stance and specially adapted hip bones that made upright locomotion easier and more energy efficient these were the very first dinosaurs and although a few species like herrerasaurus became major predators in the late triassic they still likely weren't the top predators especially considering herrerasaurus actually lived in the same place as many large archosaurs which means this 20-foot long carnivore probably wasn't the king in fact the skull of herrerasaurus has been found with bite marks on it and it's unclear whether these marks came from another herrerasaurus or something else maybe these early dinosaurs and the massive archosaur competed the same way that we see different large predators do today so even though the dinosaurs weren't on top just yet they certainly weren't confined to the shadows like the mammals during the mesozoic they just could never reach the level of dominance that they would later because of competition from other reptiles so if the dinosaurs didn't take control and drive these other strange creatures to extinction how did we end up with so few of these animal groups that were once so successful around today the triassic extinction event is something that isn't as well understood as the cretaceous or permian events there are a few theories about what exactly happened some involving a possible impact adding to things even though no crater of an extinction event causing size has ever been dated to this time so the most popular theory is that it all started with an intense jump in volcanic activity as pangaea started to rip apart and well big changes in that often lead to a domino effect it can mess with the climate by adding greenhouse gases to the atmosphere it can block out the sun and disrupt the food web by stopping photosynthesis and it can lead to acid rain which can in turn acidify the oceans apparently all these things were happening even as the very land underneath these animals feet was literally falling apart this is a lot of change and well stop me if i sound like a broken record the generalist reptiles that managed to survive the permian extinction had now just spent the past 50 million years becoming specialists themselves the strategy served them well up until around 201 million years ago it just inevitably couldn't last forever as a result of these events around 75 percent of life would die out again among them would be most of the strange reptiles like the drapanosaurs the wrinkasaurs the phytosaurs and a lot of the large carnivorous archosaurs and this time it would be the dinosaurs that would step in to take their place and now that i think about it is this really any stranger than this or this maybe we just perceive these animals as weird because they're different than what we're used to looking at but the truth is every time that there's a drop in biodiversity we see an explosion of adaptive radiation shortly after and the results are often things that we might call weird they may seem particularly strange to us today because this time was literally sandwiched in between two big mass extinctions many of these animals evolved to survive the triassic and the better majority of them didn't make it past that time so maybe had the triassic extinction never happened maybe we wouldn't see these animals as weird because we would be used to seeing them both in the fossil record as well as possibly even alive today but unfortunately for the strange specialized animals of this time it did happen and in my opinion this is the moment when the age of dinosaurs truly began when the generalist triassic dinosaurs managed to last through the volcanic armageddon that happened 201 million years ago they would inevitably expand into the vacant niches again becoming the rulers of earth until their number would come up at the end of the cretaceous this is a story as old as time and history seems to be bound to repeat itself over and over again that is until it came to be our turn because we humans are special we know better than to become too specialized to a certain way of life and even as we become increasingly dependent on technology and more and more fragile systems and we actually make changes to the world that might harm our current way of life in the future you can all sleep easy knowing that we humans cannot possibly fall victim to the exact same thing that has literally claimed 99 of all species that have ever lived on this planet see y'all next week everybody [Music] [Music] you

Channel: Paleo Analysis

Views: 1,250,320

Keywords: triassic

Id: QGy4fh81INU

Length: 12min 6sec (726 seconds)

Published: Fri Jan 28 2022

Reddit Comments

[u/nadmaximus]

None of them actually have three asses. And yet, they are at least that weird.

[u/garimascreativehub]

Nice content