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Post by dinosauria101 on Mar 2, 2020 1:04:49 GMT 5
For kekistani, if you have an issue with it, just talk to broly about it. He's open to discussion.
I'll message broly and ask him about the dorsal thing.
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Post by jdangerousdinosaur on Mar 2, 2020 1:22:04 GMT 5
Or you could ask Fran ? He did make the diagram.
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Post by dinosauria101 on Mar 2, 2020 1:25:13 GMT 5
I can possibly do that as well. Hopefully I can have both of their viewpoints soon enough.
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Post by kekistani on Mar 2, 2020 2:46:17 GMT 5
For kekistani, if you have an issue with it, just talk to broly about it. He's open to discussion. I'll message broly and ask him about the dorsal thing. I don't see a need to talk to broly about it, just pointing out an inaccuracy. As i've said multiple times before. |
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Post by dinosauria101 on Mar 2, 2020 2:53:00 GMT 5
It's not necessarily inaccurate - carcharodontosaurs have large neural spines and larger ones proportionately larger. They were also edited to remove 'weirdness', which is likely compression.
BTW, SIW's isn't the only way to get 9 tonne Carcharodontosaurus based on large headed relatives.
Spinodontosaurus obtained 13.1 meters and 8 tonnes (same as Larramendi) with Scott Hartman's Giganotosaurus as a base and an equivalent head to body ratio. Using GAT's Giganotosaurus as a base instead of Hartman's (likely the better choice as it's more well nourished in terms of soft tissue) gets 9 tonnes, which is based on a GDI.
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Post by Infinity Blade on Jul 15, 2020 3:14:26 GMT 5
This is merely a Tweet, and far from a scientific paper, but according to Denver Fowler this lacrimal is from a very large, T. rex-sized Daspletosaurus.
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Post by creature386 on Jul 15, 2020 10:35:23 GMT 5
Congratulations, viewing this on my phone woke me up from half-sleep.
Nothing we can cite in matchups or anything (yet), but definitely something that should make us hungry for future papers.
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Post by spartan on Nov 24, 2021 16:02:34 GMT 5
Is it true that Ibrahim now estimates Spinosaurus to be 10 - 11 tonnes?
Edit: Apparently he does:
"It was probably much heavier. We now have better tools to estimate the weight (e.g., a more accurate digital model). More like 10-12 metric tons. We are likely underestimating the weight of many dinosaurs, by the way."
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Post by Infinity Blade on Apr 26, 2022 20:25:52 GMT 5
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Post by Grey on May 30, 2022 3:29:02 GMT 5
thesauropodomorphlair.wordpress.com/2022/01/09/volumetric-estimate-for-giganotosaurus/Volumetric model made by SpinoinWonderLand supports the Giganotosaurus holotype at 8.17 tonnes taking into account the latest ipdated by Greg Paul and Asier Larramendi regarding the density in dinosaurs and the idea that some skeletal elements in MUCPv-ch1 are incomplete, leading to a more shrink-wrapped bauplan since years. Interestingly it was shared on twitter by Thomas Holtz, who is rather a tyrannosaur guy and usually not versed into over-optimistic figures. Scaling from this, the isolated dentary would then point to an individual tipping 9.9 tonnes. So has the carcharodontosaurids volumetr been consistently underestimated since years ? It is true that even the paper about Scotty acknowledges that MUCPv-ch1 is larger than the majority of the known T. rex individuals and that the isolated dentary could hint at a greater maximum size.  I have also seen a reddit post by Nizar Ibrahim where he acknowledges we may substantially underestimated Spinosaurus body mass since 2014 and that an updated figure may be in the 10-12 tonnes range. So, it seems like Tyrannosaurus theropod heavy weight belt is being challenged again ?  However, justly by how much those density updates would impact on the body mass estimates of the largest Tyrannosaurus Sue and Scotty ?
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Post by theropod on May 30, 2022 20:48:26 GMT 5
thesauropodomorphlair.wordpress.com/2022/01/09/volumetric-estimate-for-giganotosaurus/Volumetric model made by SpinoinWonderLand supports the Giganotosaurus holotype at 8.17 tonnes taking into account the latest ipdated by Greg Paul and Asier Larramendi regarding the density in dinosaurs and the idea that some skeletal elements in MUCPv-ch1 are incomplete, leading to a more shrink-wrapped bauplan since years. Interestingly it was shared on twitter by Thomas Holtz, who is rather a tyrannosaur guy and usually not versed into over-optimistic figures. Scaling from this, the isolated dentary would then point to an individual tipping 9.9 tonnes. So has the carcharodontosaurids volumetr been consistently underestimated since years ? It is true that even the paper about Scotty acknowledges that MUCPv-ch1 is larger than the majority of the known T. rex individuals and that the isolated dentary could hint at a greater maximum size. I have also seen a reddit post by Nizar Ibrahim where he acknowledges we may substantially underestimated Spinosaurus body mass since 2014 and that an updated figure may be in the 10-12 tonnes range. So, it seems like Tyrannosaurus theropod heavy weight belt is being challenged again ? However, justly by how much those density updates would impact on the body mass estimates of the largest Tyrannosaurus Sue and Scotty ? Well, haven't read the whole thing yet, but an interesting find. I missed the density study, but very nice find there as well. Also tangentially relevant to another project I am working on, and even if I am by first reaction a bit sceptical as to densities (and even for Sauropodsof all things!) in that paper so relatively high compared to other studies that did 3d-reconstructions of the airsac systems of dinosaurs, seems quite sound. Still within a plausible range in any case. As Spino writes, increasing density from .913 to .95 increases the mass a little bit (from 6.8 tp 7.2t to be precise), but that's not the lion's share of the added mass in his estimate. The corresponding effect of density increase from .913 to .95 for Hartman's Sue model (originally 8.4t/9200l) would be to increase its mass to ~8.7 t. However I recall the suggestions that Hartman's Sue model might also be on the conservative side (though probably less so than the Giganotosaurus, considering the well-demonstrated issues with the commonly used reconstructions of the skeleton), esp. in terms of the size of the caudofemoralis (but then again, that would likely go for Giganotosaurus as well). All that given we should assume the same density for both of them, which considering similarly good evidence for an abdominal air sac in derived carcharodontosaurs and Tyrannosaurus, I think we should. From what I remember, Scotty is ~2 percent bigger than Sue when summing up all bone measurements (as well as when comparing only the femur circumferences), so it would be around 9.3t when scaled from the above figure for Sue, but I would need to check Persons et al. again and also see if there's more detailed information from the assembled skeleton by now. I've noticed a resurgence in popular claims of T. rex being 13 m long in the last year or so, but given that isn't just a generously rounded 12.6m, I'm not sure if there is some basis for them. As for MUCPv-95, the isolated Giganotosaurus dentary, I recall Coria himself did not remember how exactly they calculated the 8% size difference between it and the holotype back then, so on the one hand it is published, but on the other hand we still don't even know what measurement it is supposed to refer to so it's hard to say what to do with it. Giganotosaurus at this point is so much in need of an updated osteological description it is not even funny any more. But was that belt ever not challenged? As you cite yourself, Persons et al. acknowledged other theropod taxa being represented by specimens larger than most T. rex individuals at the time Scotty was published. That situation never really changed, seeing how there haven't been more Giganotosaurus or Tyrannotitan finds that could have extended their size ranges downward afaik |
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Dakotaraptor
Junior Member
Used to be Metriacanthosaurus
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Post by Dakotaraptor on May 31, 2022 23:18:10 GMT 5
The corresponding effect of density increase from .913 to .95 for Hartman's Sue model (originally 8.4t/9200l) would be to increase its mass to ~8.7 t. However I recall the suggestions that Hartman's Sue model might also be on the conservative side (though probably less so than the Giganotosaurus, considering the well-demonstrated issues with the commonly used reconstructions of the skeleton), esp. in terms of the size of the caudofemoralis (but then again, that would likely go for Giganotosaurus as well). All that given we should assume the same density for both of them, which considering similarly good evidence for an abdominal air sac in derived carcharodontosaurs and Tyrannosaurus, I think we should. Maybe still not as conservative as GSP's Tyrannosaurus reconstructions from "The Tyrant Lizard King, Queen and Emperor" publication. Paul estimated FMNH PR 2081's mass of only 7.8 tonnes and RSM P2523.8 being only just as heavy. Also i am kinda surprised on BHI 3033 being one tonne heavier than CM 9830. I am not sure what method did he use for mass estimates. GDI or something else? Ps. The average femoral length of adult Tyrannosaurus would be ~1224 mm and the femoral circumference: ~526 mm based on first table from mentioned Paul et. al.'s paper. The average FC would be slightly bigger than of MUCPv-Ch1 (520 mm), but i know the femur derived estimations are most likely not as reliable as volumetric ones. Edit: It seems there are still issues on Spinosaurids being "subaqueous foragers". www.biorxiv.org/content/10.1101/2022.04.13.487781v1 |
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Post by theropod on Jun 1, 2022 1:14:28 GMT 5
No, definitely not. GSPs illustrations are always considerably leaner/more shrinkwrapped than Hartman’s (or most other modern paleoartists' for that matter).
Back in the day (as of the time he commented on Hutchinson et al.’s volumetric study) Greg Paul did Tyrannosaurus mass estimates using physical scale models (a method I think can potentially be relatively precise, but requires a lot of skill in order to not be very unreliable, though Paul is certainly someone I would trust with the technical expertise to do it right). He gives me the vibe of a bit of a traditionalist technique-wise, so perhaps he still does, but I am not sure.
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Dakotaraptor
Junior Member
Used to be Metriacanthosaurus
Posts: 193
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Post by Dakotaraptor on Jun 4, 2022 15:27:47 GMT 5
Size estimations based on dentaries (especially incomplete ones) can be very tricky. MUCPv-95 seems to be more misshaped compared to one of holotype, also we can look at mandibles of other animals (even of the same individual) eg. Allosaurus specimen SMA 0005 a.k.a Big Al Two - left dentary looks quite differently to right one. There is no suprise about it because the mandible bones were vulnerable to damage from at least several factors, especially when predators used the jaws as primally weapon to hunt down prey. Like Theropod said MUCPv-95 needs to be redescribed. Ps. Sorry if you guys think i am late, but didn't dino101 make an "big career" on other animal-related forums and deviantart? I have seen many of his size comparisons even on Reddit. Second Ps. The carnosaurs being apex scavenger is probably one of the most comical thing - almost on the same tier as BAND. Futhermore the co-author of publication tried to convince other people on Reddit that hypothesis is "good". I remember even Holtz on Twitter reacted to infamous paper. |
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Post by Infinity Blade on Jul 7, 2022 22:22:13 GMT 5
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