Spinosaurus News ~

[DrZapxX]

''Those vertebrae MAY belong to Spinosaurus but that is not 100% certain. I gave you the benefit of the doubt in assuming it did.

Also, have you considered that a density of 1 or more is still possible, even with airsacs, because most tissues as a whole are denser than water?''

The thing is, if you like it or not, they have been assigned to Spinosaurus, it's not a may, its confirmed for now, fsac kk 18118 is spinosaurus ignoring that sigilmassasaurus is spinosaurus too (fsca kk 720)

Tissues vary with density, animals with the presence of air sacs (birds) have a density less than 1.0.

''Crocodilians naturally have a density of 1.05 kg/l following Asier Larramendi's works. What I actually did was give the head and neck of SpinoInWonderland's Spinosaurus a density of 0.9 and the rest a crocodilian density to show that even with airsacs an animal can be as dense or denser than water.''





See the thing is you never really specified this in the first place, you just magically applied a 0.9 density for SpinoInWonderLand's spinosaurus, which the actual image itself contradicts, also finding total density I would still think the total density is less than 1.0, (1.05+0.9 then /2) I believe Donald Henderson and Young nailed density correctly with a pneumatic neck,heads and body (based on other theropods) while having the limbs have a specific gravity of 1.05.

''I got it from Scott Hartman's blogpost, which has been clearly linked in my first reply to you. But if we're going to reference the date of publication, Asier Larramendi's work is more recent (2016), and suggests a density of 0.95 for the majority of theropods. This density has been used on significantly more pneumatic animals than Spinosaurus (eg: Aerosteon), and therefore I find it hard to believe a much less pneumatic theropod would have been as pneumatic or less than many theropods with a lot more airsacs.''



I've already discussed the sauropod argument of yours, Hartman doesn't specify how he got these densities, also the thing you quoted was in reference to SpinoInWonderlands image, I checked Sereno et al 2008, and I'm not aware of a density value of Aerosteon.


''That paper got their densities from dead birds that had lungs inflated to the very maximum (a far cry from live, relaxed sauropods with considerably less inflation in theirs), and it failed to take into account that the tissues were denser than water. Also, it should be noted that Wedel has overestimated the airspaces if we follow Larramendi, let me get a screenshot.

*This image is copyright of its original author

Larramendi seems to have covered everything on sauropod density that I can think of, and I don't see much reason at this point to doubt a density of roughly 0.9 for sauropods. And therefore, since sauropods are MUCH more pneumatic than Spinosaurus but still have a density of 0.9, I strongly believe Spinosaurus would be a good deal denser than what you suggest.''

I checked Wedel 2005, maybe you can too, I haven't seen any quote from their methods that they used dead birds, and why did you not take into my blog post from Wedel himself the author of the paper saying if anything he UNDERestimated sauropod density https://svpow.com/2009/03/16/brachiosaur...ncomplete/ This is a clear contradiction to what you are saying, theres no direct density value for tissues they vary, Wedel literally left out air spaces and halved the air volume from the lungs, I also showed you Henderson 2003 which have densities not even from Diplodocus that have much lower total densities than 0.9.

''There exists a difference between what you and I are using as a reference. Loons do not seem to fly as much as terns, gannets, pelicans, and grebes, and they also seem to spend more time in the water and dive deeper, so it is therefore presumable they are less pneumatic because of it.

And I didn't say any airsacs at all would be detrimental, what I am saying is that an animal of 0.833 kg/l is far less realistic that 1+ kg/l given everything above. Finally, keep in mind that simply having airsacs does not prevent a density of 1 or more as shown above.''

Ummm, loons have known to fly 500 miles in a 24 hour period, they are just as aquatic as Grebes, and yes animals with air sacs have a density less than one, even with solid bones like loons.


''Or it could simply mean the size difference between those specimens is more than 32%. That would also be supported by the size of the corrected model from Henderson (2018) and some other skull reconstructions.''
Henderson got 15 metres from Ibrahim et al 2014, which in return favours 14.5 metres, which is dubious because of FSAC-KK 11888's length was not detailed on how it was 11 metres.

''t doesn't matter if it's peer reviewed or not, what does matter is if it's factually correct. And you have given no evidence suggesting it not to be other than fallaciously suggesting inaccuracy due to no peer reviewing. And show me where I'm taking anything as gospel here? I am aware nothing is truly gospel in palaeontology, so I'm simply endorsing what I find most probable.''

How do you define factually correct? In this debate you provided barely anything thats peer reviewed, I am not saying everything has to be, but the majority of your sources are poor resolution images or from people who aren't even experts, why don't you at least borrow the sources from those people which are in return peer reviewed? You see when something has been approved by two qualified experts, then it has much more reliability.
Also could you mind not stating false statements, I have specifically stated much more reasons, the 32% skull difference between FSAC-KK 11888 and MSMN v4047's skull length, as well as Henderson and Therriens separate downgrade.You seem to reference SpinoInWonderLand way too much than you should, which is almost like taking his word for complete gospel we are all aware palaeontology is a ever changing field with newer discoveries

Also it doesn't scientifically matter whats ''factual'' or not, this is science, science has to go through a process of being factual in the first place, anything that hasn't gone through the requirements is like it or not is invalid.

''Then would you mind explaining exactly why the larger estimates of theropod1 and SpinoInWonderland (especially that of SpinoInWonderland to which your argument of using a different species doesn't apply) are wrong? What you seem to be saying is that they are wrong because they are large, and you don't give any explanation for exactly why the skull reconstructions of either have been done wrongly.''

Because SpinoInWonderlands imagery placing is simply too simplistic (as if it was that simple!) aren't these skull reconstructions anyway? Theropod1's I have already explained because he/she like you claim used separate spinosaurid taxon, I am not saying that at all, if anyone you seem to be maximising the size of it, I am simply being more realistic, it is normal for prehistoric fauna to downgrade in size.

''In their sample size for the equation, they used Greg Paul's tyrannosaurid skeletals from Predatory Dinosaurs of the World, which happened to have rather short tails.''

You see I have checked Therrien et al and tried to quickly see if him and Henderson used Paul's 1988's skeletals, also I scaled Ibrahim et al 2020's spinosaurus and Pauls Tyrannosaurus, and its actually the opposite even with a curved tail it rivals the tail length,

*This image is copyright of its original author

''Can I see a source for this?''

It's literally from Henderson et al 2018

''The digital Spinosaurus model used in the current study was based on the illustration provided in Fig. S3 of the Supplementary Materials of Ibrahim et al. (2014), and the geometry of the model was taken from this figure using the slicing method of Henderson (1999). The length of the model was also based on the new restoration of Spinosaurus by Ibrahim et al. (2014). These authors state that a life size replica of Spinosaurus, generated from their new skeletal data, was ‘over 15 m in length’ (last sentence, third paragraph). As measured from the tip of its snout to the tip of its tail, the length of the present digital model is 15.55 m. ''

''I don't recall referencing Mortimer's arguments here, therefore I do not see the point of that.''
You just been using his arguments from the beginning http://dml.cmnh.org/2007Mar/msg00292.html

''What on Earth are you talking about? I gave all my sources and methods right there in the post!
If there is anything that you need clarification on, just ask.

Edit: As it turns out, the skull length on the newest skeletal of the neotype from Ibrahim et al. 2020 is 122 cm, not 112 cm. Based on that and SpinoInWonderland's 186 cm estimate for MSNM v4047's skull length, MSNM v4047 would have been 16.63 meters long and 13.7 tonnes. theropod1's skull length estimate of 177 cm also yields a very large size - 15.86 meters and 11.8 tonnes. The mean of these 2 estimates is basically the same as the corrected model from Henderson (2018), so I'd consider these further support still for very large sizes.''

Not really, barely any sources at all just poor resolution images.I am not here to dissect you, I am here to post another side to the argument on my findings so a viewer could determine for his/her self
The head NOT the skull, where does it say skull? Also this still gives a length of 160cm, I have gave my own mass estimates for 160cm (around close to 7 tonnes). Reply