hello Everyone

[Chaos Soahc]

Hello, I recently found this group, and I honestly feel so happy to become a part of this, I'm an amateur researcher and student, that is very interested in dinosaurs and biomechanics, and I'm happy that I can actually speak to some of my personal heroes (looking at you Mr. Snively). I am very grateful to hopefully get to know some of you.

I'm sorry if this sounds sorta dramatic, just very excited!

- Mr. Chaos

[Vladimír Socha]

And an adult T. rex was capable of lifting an object up to 1014 kg!

Snively, E.; Russell, A. (2007). Craniocervical feeding dynamics of Tyrannosaurus rex. Paleobiology. 33: 610-638.

Dne čtvrtek 11. prosince 2025 v 1:58:52 UTC+1 uživatel Chaos Soahc napsal:

[Chaos Soahc]

Didn't Erik Snively say that more realistic fmuscle fiber length estimates would be 1.6-1.8 times the estimate above of 1014 kg. And employing the musculature in the side of the neck, could lift like 3 tonnes. for me the real question is if it can maintain its normal horizontal posture while lifting these weights. or at least rear up slightly. Also the paper you cited above has t. rex accelerating its trunk and neck really fast, how could such a large animal perform such fast movements. Anybody who can explain this would be much appreciated!!!!

[Darius Nau]

Not sure if this point was in any way related to the earlier one of
regarding prey lifting capacities in Carcharodontosaurus (from Henderson
and Nicholls 2015) – the comment on the lifting potential in T. rex
seemed a bit disconnected from the one it was in reply to – but in case
it was, I would note that the two figures do not seem to refer to the
same thing:

Snively and Russell 2007 (p 627) estimated the forces and moments for
the neck muscles (as needed to quantify lifting ability), but they do
not appear to have subtracted any mass or moment based on the mass of
the animal’s own skull, if I am not mistaken (at least I didn’t find any
info on this calculation.

On the other hand, Henderson and Nicholls estimated the lifting
potential that was "free" for objects other than the animal’s own skull,
by subtracting the moment excerted by what they estimate to be a 332 kg
head (Henderson and Nicholls 2015, p 1373).

So in that sense, the two papers seem to quantify subtly different
things, unless I have overlooked something and Snively and Russell in
fact did subtract the head moment somewhere.
Regarding the acceleration, checking table 3 in Snively and Russell, it
furthermore appears that the head mass they estimated is lower than that
Henderson and Nicholls estimated for Carcharodontosaurus (<300 kg for
the low antorbital density models) and other published values for
(admittedly different) T. rex specimens (e.g. Hutchinson et al. 2011).
Intuitively this seems a bit strange to me, since the
Carcharodontosaurus skull is far narrower, and (even allowing for AMNH
5027 not being particularly huge for a T. rex skull) would be expected
to be relatively light (for comparison, a quick gdi of the Sue head in
Scott Hartman’s 2013 reconstruction, assuming a superellipse exponent of
2.3 for the cross-sections, would end up at about 500 kg when assuming
the same .85 SG that Henderson and Nicholls assumed for
Carcharodontosaurus).

Regarding the mass that could be lifted based on COM considerations,
Henderson and Nicholls quantified that their 6.2 ton Carcharodontosaurus
could have lifted up to 2.5 t if this were the limiting factor, so in
that sense a similar-sized Tyrannosaurus being able to lift similar
masses may seem plausible enough.

However, the exact posture the animal is envisioned in matters; the
limiting COM position tested by Henderson and Nicholls was with the COM
over a quite notably protracted foot, which makes sense for a stationary
lifting scenario where the animal is free to protract its leg and leave
it there to balance the load, but not necessarily for a scenario where
the animal is required to maintain stability during a step cycle (and
where, depending on the position of the feet, this might leave its COM
quite far anterior to either of them because there isn’t one foot that
can be left continually protracted).
Even for a larger T. rex specimen, 1-2 ton loads in the jaws would
already shift the whole-body COM quite far anterior to both its neutral
position and the acetabulum, and would require a heavily protracted leg
to balance above a foot (I am attaching a small plot visualizing this
based on a GDI of Scott Harman’s Sue skeletal).

So the animal lifting 3 tons in its jaws with one leg heavily protracted
may be viable, the animal picking up a 3 ton load and then walking
around with it less so.

IIRC Dempsey et al. 2025 also noted how a more front-heavy morphology in
Tyrannosaurus may have already required a more protracted hindlimb
posture (compared to other large theropods), so adding further mass in
its jaws / to its anterior end may be more problematic from a COM
perspective than it would have been for other theropods.


---
Dempsey, M., Cross, S.R.R., Maidment, S.C.R., Hutchinson, J.R., and
Bates, K.T. 2025. New perspectives on body size and shape evolution in
dinosaurs. Biological Reviews: brv.70026. https://doi.org/10.1111/brv.70026.

Hartman, S.A. 2013. [online]. Mass estimates: North vs South redux. Dr.
Scott Hartman’s Skeletal Drawing.com. Retrieved August 16, 2023, from
https://www.skeletaldrawing.com/home/mass-estimates-north-vs-south-redux772013.

Henderson, D.M. and Nicholls, R. 2015. Balance and Strength—Estimating
the Maximum Prey-Lifting Potential of the Large Predatory Dinosaur
Carcharodontosaurus saharicus. The Anatomical Record: 298:1367––1375.
https://doi.org/10.1002/ar.23164.

Hutchinson, J.R., Bates, K.T., Molnar, J., Allen, V., and Makovicky,
P.J. 2011. A computational analysis of limb and body dimensions in
Tyrannosaurus rex with implications for locomotion, ontogeny, and
growth. PLoS One: 6:e26037. https://doi.org/10.1371/journal.pone.0026037.

Snively, E. and Russell, A.P. 2007. Craniocervical feeding dynamics of
Tyrannosaurus rex. Paleobiology: 33:610––638.
https://doi.org/10.1666/06059.1.

On 12/15/25 21:09, Chaos Soahc wrote:
> Didn't Erik Snively say that more realistic fmuscle fiber length
> estimates would be 1.6-1.8 times the estimate above of 1014 kg. And
> employing the musculature in the side of the neck, could lift like 3
> tonnes. for me the real question is if it can maintain its normal
> horizontal posture while lifting these weights. or at least rear up
> slightly. Also the paper you cited above has t. rex accelerating its
> trunk and neck really fast, how could such a large animal perform such
> fast movements. Anybody who can explain this would be much appreciated!!!!
>
> On Sunday, December 14, 2025 at 1:36:07 AM UTC-8 Vladimír Socha wrote:
>
> And an adult T. rex was capable of lifting an object up to 1014 kg!
>
> Snively, E.; Russell, A. (2007). Craniocervical feeding dynamics

> of /Tyrannosaurus rex/ <https://www.jstor.org/stable/4500175>. /
> Paleobiology/. *33*: 610-638.

>
> Dne čtvrtek 11. prosince 2025 v 1:58:52 UTC+1 uživatel Chaos Soahc
> napsal:
>
> Hello, I recently found this group, and I honestly feel so happy
> to become a part of this, I'm an amateur researcher and student,
> that is very interested in dinosaurs and biomechanics, and I'm
> happy that I can actually speak to some of my personal heroes
> (looking at you Mr. Snively). I am very grateful to hopefully
> get to know some of you.
>
> I'm sorry if this sounds sorta dramatic, just very excited!
>
> - Mr. Chaos
>

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--
Darius Nau

Department for Paleontology, Bonn Institute of Organismic Biology
(BIOB), University of Bonn

[Chaos Soahc]

well we must not forget that theropods could just rear up, using the leg and tail musculature to shift the center of mass and provide additional muscle power to lift something. Also Erik Snively, said that a tyrannosaur could dorsiflex something around 1.8 tonnes in weight with the neck alone. I'm sure he would have stated this while acknowledging the weight of the animals head as well. I'm pretty sure the a t.rex may have still held a mostly horizontal posture if not reared up slightly to avoid instability. Though you have excellent points, especially in regard to the COM shifts that may have been a problem. I might contact Mr. Snively to see his perspective. Also still a little confused how a tyrannosaur could move its neck that rapidly? currently I'm trying to adjust Henderson's estimates by utilizing a larger muscle tension and see what it gives.