Multibody analysis and soft tissue strength refute supersonic dinosaur
tail.

Abstract

Sauropod dinosaurs are well known for their massive sizes and long
necks and tails. Among sauropods, flagellicaudatan dinosaurs are
characterized by extreme tail elongation, which has led to hypotheses
regarding tail function, often compared to a whip. Here, we analyse
the dynamics of motion of a 3D model of an apatosaurine
flagellicaudatan tail using multibody simulation and quantify the
stress-bearing capabilities of the associated soft tissues. Such an
elongated and slender structure would allow achieving tip velocities
in the order of 30 m/s, or 100 km/h, far slower than the speed of
sound, due to the combined effect of friction of the musculature and
articulations, as well as aerodynamic drag. The material properties of
the skin, tendons, and ligaments also support such evidence, proving
that in life, the tail would not have withstood the stresses imposed
by travelling at the speed of sound, irrespective of the conjectural
‘popper’, a hypothetical soft tissue structure analogue to the
terminal portion of a bullwhip able to surpass the speed of sound.

Open access:
https://www.nature.com/articles/s41598-022-21633-2

Hmm, interesting. So the tail material probably isn’t up to handling being cracked at supersonic speeds, but the speeds it can attain should be enough to smack someone pretty good. I wonder… if the tail was indeed used for defense, might that leave some sort of evidence? Perhaps there might be deformations, inflammations or some sort of scarring on the vertebrae that impacted other animals?

On the other hand, the article makes it sound as if the ends of these tails don’t tend to preserve or fossilize. Are there any at all available for study?

On Friday, December 9, 2022 at 5:37:05 AM UTC-7, Pandora wrote:
> Multibody analysis and soft tissue strength refute supersonic dinosaur
> tail.
>
> Abstract
>
> Sauropod dinosaurs are well known for their massive sizes and long
> necks and tails. Among sauropods, flagellicaudatan dinosaurs are
> characterized by extreme tail elongation, which has led to hypotheses
> regarding tail function, often compared to a whip. Here, we analyse
> the dynamics of motion of a 3D model of an apatosaurine
> flagellicaudatan tail using multibody simulation and quantify the
> stress-bearing capabilities of the associated soft tissues. Such an
> elongated and slender structure would allow achieving tip velocities
> in the order of 30 m/s, or 100 km/h, far slower than the speed of
> sound, due to the combined effect of friction of the musculature and
> articulations, as well as aerodynamic drag. The material properties of
> the skin, tendons, and ligaments also support such evidence, proving
> that in life, the tail would not have withstood the stresses imposed
> by travelling at the speed of sound, irrespective of the conjectural
> ‘popper’, a hypothetical soft tissue structure analogue to the
> terminal portion of a bullwhip able to surpass the speed of sound.
>
> Open access:
> https://www.nature.com/articles/s41598-022-21633-2