The Evolution of Therizinosaur Dinosaurs

of all the many fascinating groups of dinosaurs perhaps none or estranged as the therizinosaurus although there are some close contenders the history of research on this grouping of bizarre fluffy likely herbivorous theropods is one that stretches back decades and is filled with uncertainty these creatures were so strange that for a long time paleontologists just didn't know what they were now we have a better understanding of Pharaoh Xena saws and thanks to amazing discoveries from across the world we can begin to learn what these beasts were like how they evolved and how they're all related to other dinosaurs the anatomical features of the therizinosaurus have caused a great deal of confusion to researchers in the past as the overall morphology of the general therizinosaurus highly unusual and yet individual parts of the skeleton resemble various other dinosaur lineages in certain ways many members of this group possessed the elongated necks relatively small heads large bodies and layout of the hind feet of early sauropod morphs but while also displaying features that were similar to the owner fisca and dinosaurs such as the way their hip bones were constructed being remarkably broad and having a pubis and ischium that point backwards and their beaked jaws as a result of this strange anatomy the therizinosaurus or sickness oars as they used to be called have been classified in all kinds of different positions amongst dinosaurs but today we now know that there were theropod dinosaurs related to animals such as Oviraptor sores dromaeosaurus and alvarez sores so how did paleontologists determine what therizinosaurus figuring out how these animals evolved has been a complicated task the first therizinosaurus cribes was therizinosaurus itself in 1954 however initially it was not thought to be a dinosaur at all but instead some sort of giant turtle like a creature with enormous claws which explains its species name Kelowna formas meaning turtle like the claws of this animal were the first parts to be discovered and would likely have measured about a metre long in life when a sheath would have been present in this same description the family named therizinosaurus a was also coined it was only in 1970 that other paleontologists realized the creature these claws belonged to was not a turtle but actually a dinosaur however in 1979 a paper was published by a Mongolian paleontologist Alton Gerald pol who recognized that the fossilized remains of a dinosaur discovered in lower Cretaceous rocks in Mongolia was probably an example of a previously unknown family he named the animal sickness Oris and created the family sickness aura day to contain it the fossil remains of Sagna soros that led to this naming included the lower jaws part of the foreign hind limbs bits of ribs many vertebrae and an almost intact pelvis enabling the paleontologists to determine a decent amount of the organisms anatomy pole noticed how the limb bones of its hind legs appeared very well-suited to supporting the large body weight of a slow-moving creature and how the rear feet were not theropod like at all as theropods have highly reduced first toes instead segno Soros had a first toe that would have touched the ground in life in this initial description as well as in later papers written with another paleontologist rin-chan Baz bold pearl recognized the sickness horace was despite displaying anatomical features that appear to converge with sauropod morphs and some on officiants actually a theropod as could be seen when its skeleton was analyzed in detail however pearl also distinguished this new signature add a family from ferrocene essaouira day which at that time was now known to be a dinosaur family pointing out differences in the length of the claws in both dinosaurs as well as the morphology of the arm bones but as we'll see the groups would later become merged a larger taxonomic grouping was then named by the paleontologists in 1980 segno Soria to contain the sickness or add a family and another genus of sickness or was described Erlich asaurus a third Cygnus or genus was then named by the researchers in 1983 enigma Soros and given his own family within sickness or a day despite still maintaining that sickness ORS should be classified as theropods bars bolt did note that the anatomy of the group was incredibly unusual and that the evolution of the lineage was unique among these dinosaurs other paleontologists then also began to doubt the established position of the Sigma saurians as theropods and throughout the rest of the 80s in the early 90s a variety of alternative placements were suggested for them one of these favored by Gregory Paul proposed that since they apparently lacked any distinctive theropod like characteristics there was no real reason for them to be assigned to the group and instead they showed many ornoff ISKCON like features such as the beaked jaws as a result of this it was suggested that Cygnus oars were kind of phylogenetic intermediary between throw sauropods an outdated term for Plateosaurus like store polymorph dinosaurs and owner fisk ins which were at this time believed by some to have evolved from four sauropods some other later studies by different paleontologists also found support for sack missiles being pro sauropods and still others found them to be somewhere within saw reskins one of the major dinosaur groupings but in an unknown position it was then in the early 90s that an understanding about segno sores and therizinosaurus which is more reflective of our modern view began to emerge the discovery and naming of the Chinese tax on Alexei Soros in 1993 led the paleontologists who described it to realize that it's Anatomy was both similar in ways to segment or a day and to therizinosaurus and as such they proposed that these groupings are actually the same thing so therizinosaurus rio t as it was named first and Cygnus Oriya and Cygnus hora de are no longer in use in addition the largest superfamily of therizinosaurus was named which included Allosaurus plus the family therizinosaurus a most later studies from the 90s continued to agree that therizinosaurus were likely a group of unusual theropods and the 1999 description of bep our soros solidified this further this taxon found in China was placed as a basal therizinosaurus that these dinosaurs were true theropods with NC Laura Soria that had just convergent evolved sauropod morph and honour fisken like characteristics and not only that but the bay ep our saw a specimen also preserved the fossilized remains of feather like structures indicating that many therizinosaurus would probably have possessed a coat of downy feather integument in life so thanks to the remarkable findings of more therizinosaurus holes the relationships of these bizarre animals started to clear up the early 2000s also brought more amazing discoveries of new therizinosaurus such as the 2001 naming and description of the genus Nora like us the first therizinosaurus be found in North America and then later in 2005 FAL Korea's very early basal therizinosaurus are that enabled paleontologists to get a much better understanding of the group's origins and evolution early on in ur lineages existence after decades of contradicting views then where do we stand today well at the moment it seems the classification of therizinosaurus is relatively stable in a position placing them as many rap torrents being more derived from the alvarez swords but more basal than Oviraptor Soria and the perils however there is always a chance that the classification of these dinosaurs could alter again with future studies as they're still not represented by the best fossil material and there are a lot of unknowns yet to be discovered in this group but the more recent findings of relatively complete very basal and derived therizinosaurus does now allow us to paint a rough picture of the evolution of these most wonderful dinosaurs the basal therizinosaurus include generous such as FAL caries jian cheng asaurus bei PR soros Allosaurus and possibly martha raptor depending on which studies terminology you go by there either all non therizinosaurus therizinosaurus or some are therizinosaurus while others are therizinosaurus and yes the family super family and infraorder names get a bit annoying me confusing sometimes these more basal therizinosaurus generally tend to show anatomies that resemble features seen in their non therizinosaurus foreign relatives however they do also display adaptations that hint at the latest specialization of therizinosaurus - an omnivorous or herbivorous lifestyle Phalke aureus is a good example of this as it has a pubis that points forwards running adapted hind limbs a reduced first toe that didn't contact the ground and teeth in the front of the jaws features common to other extinct man erupt torrents but while also having an elongated neck and showing adaptations for herbivory then a 2006 study of the arms of FAL Kerris noted that this taxon and most of the early therizinosaurus still possess quite slender an elongated pectoral girdle and four limbs similar to the predatory dinosaurs they evolved from but the study also realized that several changes in the anatomy of these parts of the dinosaurs could already be recognized in these basal members including an increasing robusticity of the four limbs and pectoral girdle and an increasing flexibility of the rest the more derived therizinosaurus taxes such as segno soros aleko soros northren like us and therizinosaurus itself were capable of growing two incredibly large sizes with therizinosaurus the biggest of them all estimated at a length of 9 meters or 30 feet and about 4.5 tons in weight these later species show more specialised adaptations to their unique lifestyle amongst prehistoric theropods as probable herbivores though it's possible that they were on Everest to perhaps occasionally feeding on small animals like many traditionally herbivorous organisms actually do the characteristic traits of the derived therizinosaurus include many very small leaf shaped cheek teeth the development of a beak at the end of the rostra the very broad pelvis indicating a remarkably broad abdomen and therefore a large space for the gut and of course the recovered functionality of the first digit and adaptation of the hind limbs for weight-bearing instead of running the famous giant claws of therizinosaurus have been proposed to potentially be used for pulling down branches of vegetation and allowing the dinosaurs to feed on higher growing foliage or also as defensive structures to protect the animals from other hyper carnivorous theropods they shared their habitats with so therizinosaurus cook these beasts for more typical meat-eating fast-moving theropods two large big bellied almost panda or ground sloth like foragers with huge claws that could be used as tools or deadly weapons they're truly one of the most fascinating of all dinosaur groups which is saying something and the story of the discovery and the eventual realization of what they are is a brilliant example of scientific progress and the development of our understanding of prehistoric life well I really hope you enjoyed this video my favorite group of dinosaurs and I hope you learned something new a big thank you to our patreon supporters too especially our dinosaur tear supporters jorge logitech dominic bothy darker rots and nicole bueno 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

Channel: Ben G Thomas

Views: 179,667

Rating: 4.9641919 out of 5

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

Id: p4TrWckE5Gk

Length: 10min 43sec (643 seconds)

Published: Sun Apr 19 2020