When Giant Lizards Ruled Australia - Megalania

monitor lizards are a fantastic group of animals as they include the largest lizards alive today and their lifestyles and biology are intriguing aspects to learn about the evolutionary history of the group is also a remarkable feature especially when it comes to the giant extinct monitor known as mega lenio now monitor lizards can already get pretty huge specifically in the case of the Komodo dragon which is able to approach lengths of around three metres but in the past this group which is technically known as Verena day has actually gotten to even larger sizes however the exact extent to which they grew is something of a debate but we'll get into that later fossils from mega Lenya have been recovered from rocks in southern Australia as far back as the 1800s leading the infamous Sir Richard Owen to name it in 1859 new evidence has shown that the species actually survived until relatively more recent times than previously thought dying out around 50,000 years ago while they had first originated approximately 1.5 million years ago playing a key role in the megafauna assemblage of Pleistocene Australia the fossil remains that have been found of this animal are not particularly complete with a lot of the post cranial skeleton missing however we can get a fairly decent idea of what meg Alania probably looked like in life clearly its overall physical features would have resembled the living monitor species it is closely related to but on a large scale however there are also many differences in the morphology of Meg Alania when compared to the extant monitors for example the humerus of Meg Alania is much wider towards the elbow joint than in other species of monitor lizard and the animal also possessed a fairly pronounced crest like structure on its skull although the modern-day Parenti has a comparable structure on its snout the fossils of Meg Alania show that the crest in this animal was quite a bit larger the teeth of Meg Alania were highly curved an extremely sharp much like those of living vera Nets with an interesting texture whereby the enamel is wrinkled especially towards the base additionally these animals possessed small bits of bone embedded in the skin known as osteoderms around their head and neck another feature that appears in living members of the group now the size of Meg Alania has been a bit of a controversial topic with various estimates made over the years not having any relatively complete full skeletons does make things more difficult and so the animal must be scaled up using comparison with close relatives the range of the estimates that have been proposed in the past is quite large from 3 meters up to a ridiculous 11 meters some of the first size estimates calculated a length approaching 7 meters from head to tail with a weight of over 600 kilograms however two of the most notable estimates are ones made in 2002 and in 2004 paleontologists in 2002 calculated a much smaller total length with an average of 3.5 meters and a maximum of 4.5 meters accompanied by a maximum weight of around 330 kilograms in a 2004 book another paleontologist published more size estimates of Meg Alania coming to a range of between seven and seven point nine meters in length depending on whether the animals body proportions were closer to that of the lace monitor or the Komodo dragon still even more estimates have also placed a body length at between five and six meters therefore thanks to the incompleteness of the fossils we have it's not exactly clear what size meg Alania could have reached but it was definitely big and most probably the biggest terrestrial lizards who have ever existed so knowing all this what can we say about how meg Alania is related to other organisms well as I said before clearly it was a very net but out of the living members of this group what are its closest relatives in the past it was suggested that meg Alania could be most closely related to the Parenti which is currently the largest lizard to inhabit Australia however a more recent study has found good evidence for placing meg Alania as the sister taxon to the modern-day Komodo dragon due to similarities found in both animals skulls which would also unite all the giant indo-australian monitor lizard species together in a group however it's important to note the more complete fossil discoveries could always change what we know about the relationships of this animal in the future this brings us to another key point to understand about meg Alania as I mentioned previously saw Richard Owen first named this animal in 1859 calling it meg Alania priska however there's good reason to actually consider this specie as a member of the genus fairness the name that includes all the monitor lizard species alive today in this case meg Alania would be known as varnas Priscus however we can still refer to the animal as meg Alania since this can be used as a non scientific name the reason that many scientists think that meg Alania should be included within Varanasi is because of how closely related the animal seems to be to other monitor lizard species as I've just explained therefore if it were for some reason classified in a different genus it would make the various genus a paraphyletic taxon meaning it's not a natural grouping of taxa since it excludes certain members so it's generally preferable to include meg Alania as a part of our onus making it very honest Priscus so then what did the largest terrestrial lizard of all time feed on clearly meg Alania would have had a predatory and scavenging lifestyle similar to the Komodo dragon but to what extent well the ancient reptile probably fed on large mammals just like the extent species today does since fossilized remains of meg Elena have been found near animals such as kangaroos however it also likely preyed on a range of small to large organisms and Meg Alania also probably had a secret weapon to help in his predation again just like the Komodo dragon does venom in the modern-day dragon there is a complex system of ducts between the teeth that deliver venom into the body of the animal the creature has its jaws around though the way it utilizes this substance is quite different to how other venomous reptiles such as snakes use it in snakes the venom is directly injected into the body of the prey through the fangs with a strong piercing bite however Komodo dragons tend to have a much Messier way of doing things the Dragons will bite down and then pull back on the flesh causing lacerations that the venom secreted from the ducts between their teeth can then enter into the venom is a kind of hemotoxin meaning it stops blood from clotting so the prey end up bleeding out and becoming greatly weakened from blood loss the skulls of Komodo dragons are very well suited to this method of predation - as the relatively lightweight and adapted for resisting high pulling forces rather than applying large bite forces through comparison with the structure of the skull and teeth of Meg Alania as well as comparison through phylogenetic bracketing with related véra nerds scientists have suggested that this giant very likely had a similar predation mechanism which would also make meg Alania the biggest venomous vertebrate known to us however obviously this remarkable creature did eventually become extinct but just what could have wiped out the largest lizard of all time well a part of it might have been due to the usual culprit humans a 2015 study found a particularly young deposit of mega linear fossils were actually about fifty thousand years old adding an extra thirty thousand years onto the temporal range of the lizards and also confirming that humans in Australia did indeed overlap in time with the species although not direct evidence of a human-made extinction it does make it a possibility despite they're not actually being records of encounters between the two additionally it turns out the mega Linea would have been too slow to outrun a human putting them at risk from attacks by a species if these did indeed happen however humanity's role in the Australian megafauna extinction is a particularly heavily debated and pretty controversial topic and other means of extinction have been suggested for Meg Alania and the other animals that used to exist there such as climate change hopefully more evidence for how this giant lizard disappeared will be discovered at some point so that's Meg Alania the biggest lizard and venomous vertebrates to have ever existed it's undoubtedly a very unique and quite terrifying creature and I hope you enjoyed learning about it if you would like to learn 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] you you

Channel: Ben G Thomas

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

Id: c_7nXFf0WAs

Length: 8min 32sec (512 seconds)

Published: Sun Nov 11 2018