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The Tyrannosaur Thread- Anything T. rex or tyrannosaurid related

135

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  • Closed Accounts Posts: 1,190 ✭✭✭ Squeaky the Squirrel




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Lythronax, new "king of gore" tyrannosaur

    Expect many excessively bloody illustrations of this critter during the following months. It was not very big, but had a short wide snout and big teeth much like Tyrannosaurus rex despite being the oldest tyrannosaurid known.

    http://www.theguardian.com/science/2013/nov/06/lythronax-argestes-tyrannosaurs

    a233eb08-87a5-41a9-86c3-6637feeef8f4-460x276.jpeg

    f0d864ca-4592-41ac-a9af-3940b2474735-460x339.jpeg


  • Moderators, Society & Culture Moderators Posts: 9,366 Mod ✭✭✭✭ Manach


    Excellent article, for a second misread it and though it was name lynx-thronx - corporate sponsorship a step too far :)


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Is that the smallest tyrannosaurid known?


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    No, both Teratophoneus and Alioramus are smaller... but then again I think they're both known from juvenile individuals only...:eek:


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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    At last, a tyrannosaur trackway- may be from Albertosaurus, Gorgosaurus or Daspletosaurus- shows these theropods did travel (hunt?) in small groups at least part of the time. In this case, three tyrannosaurs aged 20 to 30 were walking side by side, although keeping a respectful distance from each other.

    http://www.plosone.org/article/info%3Adoi/10.1371/journal.pone.0103613

    http://www.theguardian.com/science/2014/jul/23/tyrannosaurs-hunted-packs-tracks-canada

    wankels-t-rex2.jpg


  • Registered Users Posts: 25,560 ✭✭✭✭ Kess73


    Cannot be the only one that thought of Phil Currie straight away?


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Still no evidence of pack hunting with adults and juveniles working together, tho :(

    IMAG0009.JPG


  • Registered Users Posts: 30,747 ✭✭✭✭ Galvasean


    Kess73 wrote: »
    Cannot be the only one that thought of Phil Currie straight away?

    I'd say he blew a gasket when he heard about it! :D


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Nothing unexpected but very interesting all the same. Daspletosaurus joins Tyrannosaurus and Gorgosaurus/Albertosaurus as a known tyrannosaur cannibal.

    http://www.independent.co.uk/news/science/giant-cannibalistic-dinosaurs-engaged-in-ritualistic-fighting-10166911.html

    _82207463_skull.png


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  • Registered Users Posts: 218 ✭✭ Linnaeus


    I maintain that violent death among dinosaurs was often provoked by members of their same species, in their rivalry over mates, food or territory. However, it seems far less likely that dinos of the same kind would have systematically hunted each other. As for cannibalism, this occurs even today among certain species, but usually after an individual dies a natural death or is killed by a predator which is not a member of the same species. I wonder if, in the case of a battle between two Daspletosaurs, the victor would have devoured his victim. There were probably ferocious fights between these beasts, but I think that most of the Daspletosaurs that got devoured were probably just scavenged upon. Well, if it was another Daspletosaur that did the scavenging, then this was cannibalism just the same.


  • Registered Users Posts: 8,551 Rubecula


    many species still practice cannibalism. No need to expect dino behaviour to be any different.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Large theropod teeth suggest previously unknown form of large theropod coexisted with tyrannosaurids in Asia during the late Cretaceous.

    http://phys.org/news/2015-05-large-theropod-teeth-upper-cretaceous.html

    1-largetheropo.jpg


  • Registered Users Posts: 218 ✭✭ Linnaeus


    China never fails to astound us, due to the vast number of significant palaeontological discoveries made there every year. Dr Xu Xing is China's foremost palaeontologist. He and his team have unearthed hundreds of new species in the last 15 years. Dr Xu is an expert on avian evolution. He has conducted profound studies on recently discovered "paravian" theropods such as the controversial Aurornis.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    This very interesting paper suggests albertosaurines such as Albertosaurus and Gorgosaurus (which may conceivably be one single genus) had a system akin to a lateral line that allowed them to better detect wind direction and align according to it during the hunt. 

    http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0187064

    731px-Drumheller_Albertosaurus_150.jpg


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    TIL Albertosaurus was named the same year Alberta became a province.

    https://royaltyrrellmuseum.wordpress.com/2018/08/12/the-discovery-of-canadas-first-known-meat-eating-dinosaur/

    Today we have many more remains and know far more about Albertosaurus. It could grow up to 9, maybe 10 meters long, had a bite force comparable to that of a great white shark, and was the dominant predator in North America from 71 to 68 million years ago. It apparently went extinct at about the same time as Tyrannosaurus rex appeared in North America.

    albertosaurus_sarcophagus_by_hodarinundu-d4ki13c.jpg

    albertosaurus-gorgosaurus_libratus.jpg


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Dynamoterror, a new tyrannosaurid.

    The name is an homage to "Dynamosaurus imperiosus", which is what T. rex was almost called at one point.

    https://gizmodo.com/rare-t-rex-relative-discovered-in-new-mexico-1829629491?utm_campaign=socialflow_gizmodo_twitter&utm_source=gizmodo_twitter&utm_medium=socialflow

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  • Registered Users Posts: 8,551 Rubecula


    interesting I wonder how they may have evolved if they had survived? so many of them.


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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    There's between 12 and 15 tyrannosaurid genera currently described, and they span a considerably time period (from around 80 to 66 million years), yet their basic body plan changes practically nothing in all that time. So you have the oldest tyrannosaurid known from good remains, Lythronax:

    lythronax-argestes-dinosaur.jpg?w968h681

    looking almost exactly as the latest tyrannosaurids such as Tarbosaurus and Tyrannosaurus:

    tarbosaur_skeletons.jpg

    I think this is a case of "if it's not broken don´t fix it". Tyrannosaurids were perfectly adapted to what they were doing, so maybe if they hadn´t gone extinct at the end of the Cretaceous, and as long as there were large prey to sustain them, chances are they would have remained pretty much the same for a very long time, like crocodiles, perhaps with outliers here and then adapted to alternate prey (fish-eating tyrannosaur?) or environment (island dwelling, mini-tyrannosaurs?)


  • Registered Users Posts: 8,551 Rubecula


    Adam Khor wrote: »
    There's between 12 and 15 tyrannosaurid genera currently described, and they span a considerably time period (from around 80 to 66 million years), yet their basic body plan changes practically nothing in all that time. So you have the oldest tyrannosaurid known from good remains, Lythronax:

    lythronax-argestes-dinosaur.jpg?w968h681

    looking almost exactly as the latest tyrannosaurids such as Tarbosaurus and Tyrannosaurus:

    tarbosaur_skeletons.jpg

    I think this is a case of "if it's not broken don´t fix it". Tyrannosaurids were perfectly adapted to what they were doing, so maybe if they hadn´t gone extinct at the end of the Cretaceous, and as long as there were large prey to sustain them, chances are they would have remained pretty much the same for a very long time, like crocodiles, perhaps with outliers here and then adapted to alternate prey (fish-eating tyrannosaur?) or environment (island dwelling, mini-tyrannosaurs?)

    you mirror my own ideas Adam. so perhaps we are not too far from the truth.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    More remains from mysterious eastern North American tyrannosauroids

    https://www.researchgate.net/publication/329687124_LARGE_BASAL_TYRANNOSAUROIDS_FROM_THE_MAASTRICHTIAN_AND_TERRESTRIAL_VERTEBRATE_DIVERSITY_IN_THE_SHADOW_OF_THE_K-PG_EXTINCTION

    The find is interesting because usually, tyrannosaurids such as T. rex are believed to have been the very last group of giant theropods to roam North America. However, these limb remains from 9+ meter theropods support the idea that eastern North America had a different fauna from the west, and that the top predator niche was filled by a different linneage of tyrannosauroids, probably more similar to Dryptosaurus:

    Dryptos2.jpg

    (Dryptosaurus having inspired this very famous Charles Knight painting popularly known as the Leaping Lizards, back when the animal was known as Laelaps):

    Dryptosaurus%2Bsaltando.jpg

    Sadly no good skeletons of Dryptosaurus and kin have been found yet, but they are believed to have been less derived than tyrannosaurids proper, and seem to have had longer, more powerful arms. Sometimes they have been reconstructed with three clawed fingers on each hand:

    photos.medleyphoto.2228493.jpg

    Or with two but proportionally much larger than in tyrannosaurids:

    Drypto+at+Dunn+1.jpg?format=1500w

    More remains needed as usual.


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Small tyrannosauroid named after Greek god of impending doom

    This is an interesting find, as it shows what tyrannosauroids looked like and what niche they occupied 96 million years ago, a time in which North America was still ruled by allosaur-type creatures.

    The new tyrannosauroid is called Moros intrepidus, was about 3.5 m long and would've been a fast running predator of small animals, thus avoiding competition with the likes of the contemporary Siats (the dominant predator at the time as far as we know).

    https://www.nationalgeographic.com/science/2019/02/new-tiny-t-rex-relative-moros-fills-north-american-fossil-gap/

    moros-intrepidus_560x280.jpg


  • Registered Users Posts: 78,049 ✭✭✭✭ Victor




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    A new study suggests the Canadian T. rex known as "RSM P2523.8" (a.k.a. "Scotty") exceeds even the famous Sue/FMNH PR2081 (until now considered the largest T. rex specimen known from decent remains) in weight, estimated at almost 9 tons.

    The body mass of RSM P2523.8 is
    thus estimated to be ~8,870 kgs (+/- 25%).

    It would thus be the heaviest T. rex on record, but not necessarily the longest or tallest:

    notably
    exceeds all T. rex specimens that have been previously categorized as robust (Larson, 2008b).
    However, in many length measurements (proximodistal femoral, tibial and jaw length) RSM
    P2523.8 is exceeded by some individuals previously categorized as gracile (Larson, 2008b).
    Whether or not a robust/gracile dichotomy exists among T. rex, these comparisons indicate that
    RSM P2523.8 was a large and robustly-proportioned individual, but likely with a shorter total
    hip-height and snout-vent length than other known specimens showing more elongate
    proportions

    https://onlinelibrary.wiley.com/doi/...6lrXXD1-pKQdk&

    This would make "RSM P2523.8/ "Scotty" heavier than any other giant theropod for which there's reliable estimates, although the study does accept that there's a much more fragmentary record for the likes of Giganotosaurus, Tyrannotitan and Spinosaurus, and new finds may show these grew just as large if not larger.

    Although RSM P2523.8 has an estimated weight more than 40% greater than the next
    largest known theropod taxon, specimens of several other theropod species (including
    Giganotosaurus carolinii and Tyrannotitan chubutensis) have femoral proportions indicative of
    body masses greater than those of most other adult T. rex specimens. As
    such, it is likely that further sampling of these other giant theropods, all of which are represented
    by fewer specimens than T. rex, may yield larger individuals that match or surpass the size of
    RSM P2523.8. In the case of Giganotosaurus carolinii, a sing dentary is known that does hint at
    a greater maximum size (Calvo, 2000).

    Scotty_Tim_Eric3.jpg?fbclid=IwAR2g0Cb72gcZsvub2fqU1sh6pdgHLYxPdMVr2PJ0tBTuUjtBUJaaw5OJjrU


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor




  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Possible tyrannosauroid tooth found in Japan

    https://www.sankei.com/life/photos/190419/lif1904190032-p3.html

    lif1904190032-p3.jpg

    20190419-00000539-san-000-2-view.jpg


  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    T. rex specimen for sale on eBay, and paleontologists of course are less than happy:

    https://www.livescience.com/65296-baby-t-rex-ebay-auction.html

    Although listed as a "baby T. rex", in reality it would have been 4 years old or so at the moment of death, and around 4.5 m long, so hardly a baby anymore; still, juvenile T. rex specimens are extremely rare. Hatchlings, as far as I know, have never been discovered, and neither have nests or eggs, meaning practically everything about T. rex' early life is unknown.

    Here's a reconstruction of this particular specimen, nicknamed "Baby Bob" and "Son of Samson" (Samson being another T. rex that was also auctioned):

    post-10935-0-35517400-1455312442.jpg

    And here's the actual fossil:

    DT8p3JxXUAALkDR.jpg


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  • Moderators, Science, Health & Environment Moderators Posts: 5,279 Mod ✭✭✭✭ Adam Khor


    Small, potential ancestor to T. rex found in New Mexico, named Suskityrannus or "coyote-like tyrant".

    https://www.pbs.org/wgbh/nova/article/suskityrannus-hazelae/

    img_evelasco_20190506-160519_imagenes_lv_terceros_suskityrannus_hazelae_trees-kpSC-U4620721585050KD-992x558@LaVanguardia-Web.jpg

    At only one meter tall at the hips it was only a fraction of T. rex's size but is very similar, proportion-size, to juvenile T. rex.

    Here's the fragments of Suskityrannus' skeleton compared to T. rex's jaw:

    IMG_3511.width-800.jpg


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